(19)
(11)EP 3 190 714 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
05.12.2018 Bulletin 2018/49

(21)Application number: 14902686.6

(22)Date of filing:  28.09.2014
(51)International Patent Classification (IPC): 
H04B 3/48(2015.01)
H04N 21/61(2011.01)
H04L 25/02(2006.01)
(86)International application number:
PCT/CN2014/087701
(87)International publication number:
WO 2016/045131 (31.03.2016 Gazette  2016/13)

(54)

METHOD AND APPARATUS FOR ACQUIRING CHANNEL TRANSMISSION CHARACTERISTICS

VERFAHREN UND VORRICHTUNG ZUR ERFASSUNG VON MERKMALEN EINES ÜBERTRAGUNGSKANALS

PROCÉDÉ ET APPAREIL D'ACQUISITION DE CARACTÉRISTIQUES DE TRANSMISSION DE CANAL


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43)Date of publication of application:
12.07.2017 Bulletin 2017/28

(73)Proprietor: Huawei Technologies Co., Ltd.
Longgang District Shenzhen, Guangdong 518129 (CN)

(72)Inventors:
  • ZHANG, Xiaolong
    Shenzhen Guangdong 518129 (CN)
  • LV, Jie
    Shenzhen Guangdong 518129 (CN)

(74)Representative: Epping - Hermann - Fischer 
Patentanwaltsgesellschaft mbH Schloßschmidstraße 5
80639 München
80639 München (DE)


(56)References cited: : 
EP-A1- 2 717 486
CN-A- 101 755 389
CN-A- 104 007 705
CN-A- 101 056 219
CN-A- 103 001 666
US-A1- 2012 243 597
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] The present invention relates to the communications technologies, and in particular, to a channel transmission characteristic obtaining method and apparatus.

    BACKGROUND



    [0002] A hybrid fiber-coaxial (HFC) network technology is an economical and practical integrated digital service broadband network access technology. An HFC generally includes three parts: an optical fiber trunk, a coaxial cable branch, and a user cable distribution network. A program signal from a cable television station is first converted into an optical signal for transmission on the trunk. The optical signal is converted into an electrical signal in a user area, and after being distributed by a distributor, is sent to a user by using a coaxial cable. FIG. 1 is a schematic diagram of a typical HFC network. As shown in FIG. 1, the HFC network includes the following devices and components: a network management system, a proactive network maintenance (PNM) server, a cable modem termination system (CMTS), an optical station, a cable modem (CM), a user-side set top box (STB), a personal computer (PC), and components such as a fiber (fiber), a coaxial cable (cable), an amplifier, and an attenuator (the components are not shown one by one in the figure). It can be seen that the CMTS is located on a metropolitan area network side and is also referred to as a head end, and the CM is located on a user end.

    [0003] A transmission characteristic refers to a relationship between an input signal and an output signal when a signal passes through a device or a channel, and is a parameter that reflects transmission quality and performance of the device or the channel. For the HFC network, the transmission characteristic mainly refers to a relationship curve between an attenuation characteristic and a frequency when a signal passes through the network. This relationship is also referred to as an amplitude-frequency characteristic (amplitude and frequency curve) of the signal. The devices, components, and cables in the HFC network have respective transmission characteristics, and a network structure is complex, resulting in different transmission characteristics from users (CM) to a head end (CMTS).

    [0004] A transmission characteristic from the CM to the head end is widely used in designing and debugging of the HFC network, and in future operation and maintenance. When the HFC network is designed and debugged for the first time, proper components and an optimal cascading manner need to be selected for installation and layout, to ensure similar path losses of all users. An optical device and an amplifier further need to be debugged after the installation, to finally maintain consistency of transmission characteristics of all the users. In an operation and maintenance aspect, as network usage time goes by, characteristics of all components have different levels of changes and distortion (because of aging, water corrosion, cable bent, and the like), finally resulting in distortion of transmission characteristic curves of all the users. For example, fluctuation or unflatness appears, and some users even encounter relatively severe faults. In this case, locations of the faults need to be analyzed by analyzing the transmission characteristic of the network, to perform line adjustment.

    [0005] To obtain the transmission characteristic from the CM to the head end, in the prior art, a network signal is usually measured and analyzed by using a network analyzer or a spectrum analyzer. However, this manner can only be performed when the entire HFC network is in a power-off state, and cannot be performed when the HFC is in a working state. In addition, this method requires that there is no intrusion signal in the network, such as noise interference. If there is an intrusion signal, the intrusion signal is measured by an instrument. Consequently, a line characteristic cannot be correctly reflected, resulting in inaccurate measurement and analysis.

    [0006] US 2012/0243597 A1 relates to upstream frequency response measurement and characterization. Signaling is provided between respective communication devices within a communication system. Based upon at least one of these signals, one of the communication devices captures a number of sample sets corresponding thereto at different respective frequencies (e.g., a different respective center frequencies, frequency bands, etc.). Then, spectral analysis is performed with respect to each of the sample sets to generate a respective and corresponding channel response estimate there from. After this number of channel response estimates is determined, they are combined or splice together to generate a full channel response estimate. In implementations including an equalizer, different respective sample sets may correspond to those that have undergone equalization processing and those that have not.

    SUMMARY



    [0007] Embodiments of the present invention provide a channel transmission characteristic obtaining method and apparatus according to the attached claims, to obtain a channel transmission characteristic when an HFC network is in a working state, and improve accuracy of an analysis result.

    [0008] According to a first aspect, an embodiment of the present invention provides a channel transmission characteristic obtaining method, including:

    obtaining transmission characteristic curves of at least two channels from a cable modem to a cable modem termination system of a hybrid fiber-coaxial network in a channel scanning manner, where one characteristic curve reflects amplitudes of one channel at all frequencies, the at least two channels form one contiguous frequency band, and frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude;

    translating the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve; and

    using the continuous curve as a transmission characteristic curve of the contiguous frequency band.



    [0009] Translating the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve includes:

    calculating a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and using the difference as a first distance MovedV;

    fixing a transmission characteristic curve of one channel in the any two adjacent channels, and translating a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band including the two adjacent channels; and

    continuing to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band including the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.



    [0010] If there are multiple same frequencies on the transmission characteristic curves of the two adjacent channels, the calculating a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and using the difference as a first distance MovedV includes:

    calculating differences between amplitudes corresponding to all the same frequencies on the transmission characteristic curves of the adjacent channels; and

    calculating an average value of the differences between the amplitudes corresponding to all the same frequencies, and using the average value as the first distance MovedV.



    [0011] According to the first aspect, in a first possible implementation manner, the fixing a transmission characteristic curve of one channel in the any two adjacent channels includes: fixing a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels.

    [0012] According to any one of the first aspect, or the first possible implementation manner of the first aspect, in a second possible implementation manner, the obtaining transmission characteristic curves of at least two channels from a cable modem to a cable modem termination system includes:

    collecting pre-equalization coefficients of the at least two channels in the cable modem; and

    obtaining the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels.



    [0013] According to any one of the first aspect, or the first to the second possible implementation manners of the first aspect, in a third possible implementation manner, the method further includes:

    collecting transmit power of the cable modem and receive power of the cable modem termination system that are corresponding to each of the channels;

    obtaining line attenuation power according to the transmit power and the receive power corresponding to each of the channels; and

    shifting upward the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain an absolute value of a transmission characteristic of the frequency band.



    [0014] According to a second aspect, an embodiment of the present invention provides a channel transmission characteristic obtaining apparatus, including:

    an obtaining module, configured to obtain transmission characteristic curves of at least two channels from a cable modem to a cable modem termination system of a hybrid fiber-coaxial network in a channel scanning manner, where one characteristic curve reflects amplitudes of one channel at all frequencies, the at least two channels form one contiguous frequency band, and frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude; and

    a processing module, configured to translate the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve; and use the continuous curve as a transmission characteristic curve of the contiguous frequency band.



    [0015] The processing module is specifically configured to:

    calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV;

    fix a transmission characteristic curve of one channel in the any two adjacent channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band including the two adjacent channels; and

    continue to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band including the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.



    [0016] If there are multiple same frequencies on the transmission characteristic curves of the at least two adjacent channels, the processing module is specifically configured to:

    calculate differences between amplitudes corresponding to all the same frequencies on the transmission characteristic curves of the adjacent channels; and

    calculate an average value of the differences between the amplitudes corresponding to all the same frequencies, and use the average value as the first distance MovedV.



    [0017] According to the second aspect, in a first possible implementation manner, the processing module is specifically configured to:
    fix a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels.

    [0018] According to any one of the second aspect, or the first possible implementation manner of the second aspect, in a second possible implementation manner, the obtaining module is specifically configured to:

    collect pre-equalization coefficients of the at least two channels in the cable modem; and

    obtain the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels.



    [0019] According to any one of the second aspect, or the first to the second possible implementation manners of the second aspect, in a third possible implementation manner, the obtaining module is further configured to:

    collect transmit power of the cable modem and receive power of the cable modem termination system that are corresponding to each of the channels; and

    the processing module is further configured to:

    obtain line attenuation power according to the transmit power and the receive power corresponding to each of the channels; and

    shift upward the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain an absolute value of a transmission characteristic of the frequency band.



    [0020] According to a third aspect, an embodiment of the present invention provides a server in accordance with the second aspect.

    [0021] According to the channel transmission characteristic obtaining method and apparatus provided in the embodiments of the present invention, a pre-equalization coefficient of each frequency band is collected according to a channel scanning method, and a transmission characteristic of each frequency band is obtained according to the pre-equalization coefficient. Then, translation processing is performed on a transmission characteristic curve of each frequency band, to obtain a transmission characteristic curve of an entire frequency band. The channel scanning method can be performed when an HFC network is in a working state, and the network does not need to be powered off. In addition, the collected pre-equalization coefficient is unrelated to network noise, and can reflect a line transmission characteristic. Therefore, compared with a prior-art method for measurement by using an instrument, accuracy of an analysis result can be improved.

    BRIEF DESCRIPTION OF DRAWINGS



    [0022] To describe the technical solutions in the embodiments of the present invention or in the prior art more clearly, the following briefly describes the accompanying drawings required for describing the embodiments or the prior art. Apparently, the accompanying drawings in the following description show some embodiments of the present invention, and persons of ordinary skill in the art may still derive other drawings from these accompanying drawings without creative efforts.

    FIG. 1 is a schematic diagram of a typical HFC network;

    FIG. 2 is a flowchart of a channel transmission characteristic obtaining method according to an embodiment of the present invention;

    FIG. 3 is a schematic diagram of an overlapped area of two adjacent channels;

    FIG. 4 is a schematic diagram of transmission characteristic curves of multiple channels in a CM;

    FIG. 5 is a transmission characteristic curve that is obtained by means of translation and that is of an entire to-be-measured frequency band;

    FIG. 6 is a channel transmission characteristic absolute value curve corresponding to the channel transmission characteristic curve shown in FIG. 5;

    FIG. 7 is a schematic structural diagram of a channel transmission characteristic obtaining apparatus according to an embodiment of the present invention; and

    FIG. 8 is a schematic structural diagram of a server that can be used for obtaining a channel transmission characteristic according to an embodiment of the present invention.


    DESCRIPTION OF EMBODIMENTS



    [0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following clearly and completely describes the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

    [0024] FIG. 2 is a flowchart of a channel transmission characteristic obtaining method according to an embodiment of the present invention. As shown in FIG. 2, the method in this embodiment may be completed by a server disposed on a network side or a channel transmission characteristic obtaining apparatus at another location of an HFC network. The method in this embodiment may include the following steps.

    [0025] Step 201: Obtain respective transmission characteristic curves of at least two channels in a CM in a channel scanning manner, where the at least two channels form one contiguous frequency band.

    [0026] One characteristic curve reflects amplitudes of one channel at all frequencies. Frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude. That is, the transmission characteristic curves of the at least two channels obtained in step 201 may be located in a same coordinate system. In this way, in the coordinate system, frequency units indicated by horizontal coordinates of all transmission characteristic curves are the same, and amplitude units indicated by vertical coordinates of all the transmission characteristic curves are also the same.

    [0027] A frequency located at the most central location on a channel may be referred to as a central frequency of the channel. Central frequencies of channels in the CM may be set according to a specific rule. For example, the frequencies may be set in an equal-difference increasing or decreasing manner, to ensure that an entire to-be-measured frequency band is covered. In addition, to make a finally obtained transmission characteristic curve of the entire frequency band continuous, for any two adjacent channels, a last frequency of a previous channel and a first frequency of a following channel need to be overlapped. To improve accuracy of a result, the two channels may further overlap at a specific length. As shown in FIG. 3, FIG. 3 is a schematic diagram of an overlapped area of two adjacent channels.

    [0028] In specific implementation, for an uplink frequency band whose frequency range is 5 to 42 MHz, to improve efficiency, a bandwidth of each channel may be set to maximum, that is, 6.4 MHz, and central frequencies of all channels may be respectively 8.2 MHz, 11.4 MHz, 14.6 MHz, ..., 33.8 MHz, and 37 MHz.

    [0029] It should be noted that the foregoing channels may be set by controlling a CMTS in a network management device. The network management device determines a quantity of uplink channels, and a central frequency of each of the uplink channels. In actual network operation, the CM and the CMTS transmit information according to these settings. In addition, general channel settings can meet a channel requirement in this embodiment of the present invention. Therefore, in specific implementation, an existing channel and frequency can be directly used. After the channels and the frequencies are determined, transmission characteristic curves of the foregoing set channels may be collected.

    [0030] Specifically, if an in-band frequency response of a channel, that is, a transmission characteristic curve of each channel, can be directly collected in the network, the transmission characteristic curve of each channel can be directly collected in step 201. If the in-band frequency response of the channel cannot be directly collected in the network, step 201 may include: collecting pre-equalization coefficients of the at least two channels in the CM in the channel scanning manner; and obtaining the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels. Specifically, Fourier Transform may be performed on the collected pre-equalization coefficients to obtain corresponding in-band frequency responses, that is, the transmission characteristic curves. FIG. 4 is a schematic diagram of transmission characteristic curves of multiple channels in a CM.

    [0031] The transmission characteristic curves, of the multiple channels, obtained according to pre-equalization coefficients or directly collected are shown in FIG. 4.

    [0032] Step 202: Translate the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve.

    [0033] In a special case, two adjacent channels are connected head-to-tail, that is, the two adjacent channels have only one overlapped frequency. Step 202 may include the following substeps:
    Calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two channels, and use the difference as a first distance MovedV; and fix a transmission characteristic curve of one of the channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two channels overlapped.

    [0034] In a more common case, an overlapped frequency band between adjacent channels is a relatively long frequency band, that is, there are multiple same frequencies on the transmission characteristic curves of the at least two channels. The calculating a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two channels, and using the difference as a first distance MovedV includes the following substeps:
    Calculate differences between amplitudes corresponding to all same frequencies on the transmission characteristic curves of the any two channels; and then calculate an average value of the differences between the amplitudes corresponding to all the same frequencies, and use the average value as the first distance MovedV.

    [0035] For step 202, an optional translation manner is as follows: Translate transmission characteristic curves of two adjacent channels in order, until all curves form one continuous curve. Specifically, step 202 may include the following substeps:
    Calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV.

    [0036] Fix a transmission characteristic curve of one channel in the any two adjacent channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band including the two adjacent channels.

    [0037] Continue to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band including the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.

    [0038] In specific implementation, the fixing a transmission characteristic curve of one channel in the any two adjacent channels may include: fixing a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels. The channel that has a smaller frequency is as follows: If a minimum frequency value of a frequency corresponding to a transmission characteristic curve is smaller than a minimum frequency value on another transmission characteristic curve, a channel corresponding to the transmission characteristic curve that has the frequency whose frequency value is smaller is the channel that has a smaller frequency.

    [0039] For example, there are three channels, respectively referred to as a first channel, a second channel, and a third channel. The first channel and the second channel are adjacent channels. The second channel and the third channel are adjacent channels. A first distance between the first channel and the second channel may be calculated and marked as MovedV2, and a first distance between the second channel and the third channel may be calculated and marked as MovedV3. A transmission characteristic curve of the second channel may be first fixed, and a transmission characteristic curve of the third channel is translated in an amplitude direction by MovedV3, to make amplitudes corresponding to a same frequency on the transmission characteristic curves of the third channel and the second channel overlapped. In this case, a transmission characteristic curve corresponding to a frequency band including the second channel and the third channel is formed. Then, a transmission characteristic curve of the first channel is fixed, and the transmission characteristic curve corresponding to the frequency band including the second channel and the third channel is translated in an amplitude direction by MovedV2, to make amplitudes corresponding to a same frequency on the transmission characteristic curves of the second channel and the first channel overlapped. In this case, a transmission characteristic curve corresponding to a frequency band including the first channel, the second channel, and the third channel is formed.

    [0040] Optionally, distances (that is, second distances) by which the transmission characteristic curves of all the channels need to be translated are separately calculated, and then the curves are translated by their respective second distances, to obtain a transmission characteristic curve of a to-be-measured contiguous frequency band. Specific operations may be as follows. If there are N channels, N is an integer greater than 1, a channel whose central frequency has a minimum frequency value is a first channel, and other channels are sorted in ascending order of central frequencies, where the central frequency refers to a frequency located at the most central location on a channel, step 202 may include the following substeps:
    Calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV, where a first distance corresponding to a transmission characteristic curve of a jth channel is MovedVj, and j is an integer greater than 1 and less than or equal to N.

    [0041] Calculate a second distance corresponding to a transmission characteristic curve of an ith channel according to the following formula:

    where MovedPoweri is the second distance corresponding to the transmission characteristic curve of the ith channel, and i is an integer greater than 1 and less than or equal to N.

    [0042] Fix a transmission characteristic curve of the first channel, and separately translate transmission characteristic curves of the other channels in an amplitude direction by second distances corresponding to the transmission characteristic curves of the channels, to make amplitudes corresponding to same frequencies on the transmission characteristic curves of all the channels overlapped, so as to form one continuous curve.

    [0043] Transmission characteristic curves of multiple channels in a CM shown in FIG. 4 are used as an example in the following to describe this manner in step 202 in detail.

    [0044] In step 202, all transmission characteristic curves need to be translated in an amplitude direction by using respective central frequencies as axes. A translation objective is to make curves corresponding to overlapped frequency bands overlapped, to obtain one continuous curve.

    [0045] In a translation process, in transmission characteristic curves of two adjacent channels, a quantity by which a following curve needs to be translated relative to a previous curve is referred to as a first distance, that is, MovedV. A method for calculating the first distance MovedV may be as follows: Perform a subtraction operation between values of amplitudes corresponding to an overlapped part of frequencies on these two curves, and then calculate an average value. A specific translation process may be controlled by a program, and specific steps may be as follows.

    [0046] It is assumed that a channel that has a minimum central frequency is a first channel, and other channels are sorted in ascending order of central frequencies. Frequencies in an overlapped area of a (k-1)th curve and a kth curve are f=[fk,i, fk,2, ..., fk,m], m frequencies in total. Amplitude values corresponding to these frequencies on the (k-1)th curve are Vk-1=[Vk-1,1, Vk-1,2, ..., Vk-1,m], and amplitude values corresponding to these frequencies on the kth curve are Vk=[Vk,1, Vk,2, ..., Vk,m]. Curve overlapping needs to be performed in the overlapped area, and a first distance MovedVk by which the kth curve needs to be translated relative to the (k-1)th curve is:



    [0047] According to formula (1), a first distance of a second curve relative to a first curve may be calculated as MovedV2, a first distance of a third curve relative to the second curve is MovedV3. By analogy, a set c of first distances MovedV of all two adjacent curves may be calculated as follows:

    where N is a quantity of channels.

    [0048] Then, the first curve is used as a reference, that is, the first curve is not translated. First distances MovedV of other curves are gradually accumulated, that is, a relative translation quantity of each curve is a sum of a first distance of the curve and first distances of all curves previous to the curve. A final relative translation quantity of each curve, that is, a second distance MovedPower, is calculated to combine all the curves, and obtain a transmission characteristic curve of an entire frequency band. The second distance MovedPower of each curve is as follows:
    If a second distance MovedPower of an ith curve is MovedPoweri, a calculation method of MovedPoweri is the following formula (3):



    [0049] A set of the second distances of all the curves is:



    [0050] According to formula (4), the translation in step 202 can be completed, to obtain the transmission characteristic curve of the to-be-measured frequency band.

    [0051] If there are two to-be-measured channels, only a transmission characteristic curve of a following channel needs to be shifted, that is, only one first distance MovedV needs to be calculated. Therefore, a summation of all first distances MovedV does not need to be calculated. Only a transmission characteristic curve of a previous channel needs to be fixed, and the transmission characteristic curve of the following channel is translated in an amplitude direction by the first distance MovedV. Consequently, frequency-overlapped parts of the transmission characteristic curves of the two channels can be overlapped.

    [0052] Step 203: Use the continuous curve as a transmission characteristic curve of the contiguous frequency band.

    [0053] Similarly, the transmission characteristic curves of the multiple channels in the CM shown in FIG. 4 are used as an example. A continuous curve obtained according to the translation in step 202 is shown in FIG. 5. FIG. 5 is a transmission characteristic curve that is obtained by means of translation and that is of an entire to-be-measured frequency band.

    [0054] It should be noted that the obtained transmission characteristic curve of the to-be-measured frequency band in this case is a relative value of a transmission characteristic, not an absolute value. That is, a location corresponding to each frequency on the curve can reflect a transmission characteristic of a channel. According to a shape of the curve, quality of the channel can be analyzed, and fault diagnosis and locating, line adjustment, and the like can be performed. However, an amplitude of the curve is not an actual receive level. To obtain an absolute value of the transmission characteristic of the to-be-measured frequency band, the following optional steps 204 to 206 need to be executed.

    [0055] Step 204 (optional): Collect transmit power and receive power corresponding to each of the channels.

    [0056] For an uplink channel, in step 204, transmit power of the CM and receive power of a CMTS that are corresponding to each of the channels are collected. For a downlink channel, in step 204, transmit power of the CMTS and receive power of the CM that are corresponding to each of the channels are collected.

    [0057] Step 205 (optional): Obtain line attenuation power according to the transmit power and the receive power corresponding to each of the channels.

    [0058] Step 206 (optional): Shift upward the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain an absolute value of a transmission characteristic of the frequency band.

    [0059] A channel transmission characteristic curve shown in FIG. 5 is used as an example for description. If calculated line attenuation power is 44 dB, the channel transmission characteristic curve shown in FIG. 5 may be translated upward by 44 dB, to obtain a curve shown in FIG. 6. FIG. 6 is a channel transmission characteristic absolute value curve corresponding to the channel transmission characteristic curve shown in FIG. 5.

    [0060] According to this embodiment of the present invention, a transmission characteristic curve of each channel on a to-be-measured frequency band in a CM is obtained, and a transmission characteristic curve of the entire to-be-measured frequency band is obtained in a curve translation manner. Because a data collection process and a data processing process can be performed when an HFC network is in a working state, the transmission characteristic curve of the to-be-measured frequency band can be obtained when the HFC network is in a working state. In addition, a manner of collecting a pre-equalization coefficient of a channel or directly collecting in-band frequency response data of a channel is used instead of a manner of measuring a signal by using an external instrument, and there is no impact caused by noise during instrument measurement. Therefore, compared with a transmission characteristic curve that is obtained by using a spectrum analyzer or a network analyzer in the prior art, the transmission characteristic curve obtained according to the method in this embodiment of the present invention has higher accuracy.

    [0061] FIG. 7 is a schematic structural diagram of a channel transmission characteristic obtaining apparatus according to an embodiment of the present invention. As shown in FIG. 7, an apparatus 700 in this embodiment may include an obtaining module 701 and a processing module 702.

    [0062] The obtaining module 701 may be configured to obtain transmission characteristic curves of at least two channels in a cable modem in a channel scanning manner, where one characteristic curve reflects amplitudes of one channel at all frequencies, the at least two channels form one contiguous frequency band, and frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude.

    [0063] The processing module 702 may be configured to translate the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve; and use the continuous curve as a transmission characteristic curve of the contiguous frequency band.

    [0064] The apparatus in this embodiment may be configured to execute the technical solutions in FIG. 2 and the foregoing method embodiment. Implementation principles of the apparatus and the method embodiment are similar. Functions of each function module of the apparatus may be specifically implemented according to the method in the foregoing method embodiment. For a specific implementation process thereof, refer to related description in the foregoing embodiment, and details are not described herein.

    [0065] According to the apparatus in this embodiment, an obtaining module obtains a transmission characteristic curve of each channel on a to-be-measured frequency band in a CM, and a processing module obtains a transmission characteristic curve of the entire to-be-measured frequency band in a curve translation manner. Because a data collection process and a data processing process can be performed when an HFC network is in a working state, the transmission characteristic curve of the to-be-measured frequency band can be obtained when the HFC network is in a working state. In addition, a manner of collecting a pre-equalization coefficient of a channel or directly collecting in-band frequency response data of a channel is used instead of a manner of measuring a signal by using an external instrument, and there is no impact caused by noise during instrument measurement. Therefore, compared with a transmission characteristic curve obtained by using a spectrum analyzer or a network analyzer in the prior art, the transmission characteristic curve obtained in this embodiment of the present invention has higher accuracy.

    [0066] Optionally, the processing module 702 in the apparatus in the foregoing embodiment may be specifically configured to:

    calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV;

    fix a transmission characteristic curve of one channel in the any two adjacent channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band including the two adjacent channels; and

    continue to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band including the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.



    [0067] For ease of implementation, the processing module 702 may be specifically configured to:
    fix a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels, and translate a transmission characteristic curve of the other channel.

    [0068] Further, the processing module 702 in the apparatus in the foregoing embodiment may be specifically configured to:

    calculate a difference between amplitudes corresponding to a same frequencies on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV;

    fix a transmission characteristic curve of one channel in the any two adjacent channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequencies on the transmission characteristic curves of the two adjacent channels overlapped; and

    repeatedly execute the foregoing steps, until transmission characteristic curves corresponding to all channels form one continuous curve.



    [0069] Optionally, if there are N channels, N is an integer greater than 1, a channel that has a minimum central frequency is a first channel, and other channels are sorted in ascending order of frequency values of central frequencies, the processing module 702 in the apparatus in the foregoing embodiment may be specifically configured to:

    calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV, where a first distance corresponding to a transmission characteristic curve of a jth channel is MovedVj, and j is an integer greater than 1 and less than or equal to N;

    calculate a second distance corresponding to a transmission characteristic curve of an ith channel according to the following formula:

    where MovedPoweri is the second distance corresponding to the transmission characteristic curve of the ith channel, and i is an integer greater than 1 and less than or equal to N; and

    fix a transmission characteristic curve of the first channel, and separately translate transmission characteristic curves of the other channels in an amplitude direction by second distances corresponding to the transmission characteristic curves of the channels, to make amplitudes corresponding to same frequencies on the transmission characteristic curves of all the channels overlapped, so as to form one continuous curve.



    [0070] Further, if there are multiple same frequencies on the transmission characteristic curves of the at least two channels, the processing module 702 is specifically configured to:

    calculate differences between amplitudes corresponding to all the same frequencies on the transmission characteristic curves of the adjacent channels; and

    calculate an average value of the differences between the amplitudes corresponding to all the same frequencies, and use the average value as the first distance MovedV.



    [0071] Further, if an in-band frequency response of a channel cannot be directly collected in a network, the obtaining module 701 may be specifically configured to:

    collect pre-equalization coefficients of the at least two channels in the cable modem; and

    obtain the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels.



    [0072] It should be noted that the obtained transmission characteristic curve of the to-be-measured frequency band in this case is a relative value of a transmission characteristic, not an absolute value. That is, a location corresponding to each frequency on the curve can reflect a transmission characteristic of a channel. According to a shape of the curve, quality of the channel can be analyzed, and fault diagnosis and locating, line adjustment, and the like can be performed. However, an amplitude of the curve is not an actual receive level. To obtain an absolute value of the transmission characteristic of the to-be-measured frequency band, optionally, the obtaining module 701 may be further configured to:
    collect transmit power of the cable modem and receive power of a cable modem termination system that are corresponding to each of the channels.

    [0073] The processing module 702 may be further configured to:

    obtain line attenuation power according to the transmit power and the receive power corresponding to each of the channels; and

    shift upward the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain the absolute value of the transmission characteristic of the frequency band.



    [0074] FIG. 8 is a schematic structural diagram of a server that can be used for obtaining a channel transmission characteristic according to an embodiment of the present invention. As shown in FIG. 8, a server 800 includes an interface circuit 801 and a processor 802. A memory 803 and a bus 804 are also shown in the figure. The processor 802, the interface circuit 801, and the memory 803 are connected by using the bus 804 to perform mutual communication.

    [0075] The bus 804 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 804 may be classified into an address bus, a data bus, a control bus, and the like. For ease of representation, only one bold line is used in FIG. 8 for representation, but it does not indicate that there is only one bus or one type of bus.

    [0076] The memory 803 is configured to store executable program code, and the program code includes a computer operation instruction. The memory 803 may include a high-speed RAM, and may further include a non-volatile memory, such as at least one disk memory.

    [0077] The processor 802 may be a central processing unit (CPU), or may be an application-specific integrated circuit (ASIC), or may be configured as one or more integrated circuits that implement this embodiment of the present invention.

    [0078] The interface circuit 801 is configured to obtain transmission characteristic curves of at least two channels in a cable modem in a channel scanning manner, where one characteristic curve reflects amplitudes of one channel at all frequencies, the at least two channels form one contiguous frequency band, and frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude.

    [0079] The processor 802 is configured to translate the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all the transmission characteristic curves overlapped, so as to form one continuous curve; and use the continuous curve as a transmission characteristic curve of the frequency band. Optionally, the processor 802 is specifically configured to:

    calculate a difference between amplitudes corresponding to a same frequencies on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV;

    fix a transmission characteristic curve of one channel in the any two adjacent channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequencies on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band including the two adjacent channels; and

    continue to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band including the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.



    [0080] For ease of implementation, the processor 802 may be specifically configured to:
    fix a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels.

    [0081] In an optional embodiment, there are N channels, and N is an integer greater than 1. A channel that has a central frequency whose frequency value is minimum is a first channel, and other channels are sorted in ascending order of frequency values of central frequencies. The processor 802 is specifically configured to:

    calculate a difference between amplitudes corresponding to a same frequency on transmission characteristic curves of any two adjacent channels, and use the difference as a first distance MovedV, where a first distance corresponding to a transmission characteristic curve of a jth channel is MovedVj, and j is an integer greater than 1 and less than or equal to N;

    calculate a second distance corresponding to a transmission characteristic curve of an ith channel according to the following formula:

    where MovedPoweri is the second distance corresponding to the transmission characteristic curve of the ith channel, and i is an integer greater than 1 and less than or equal to N; and

    fix a transmission characteristic curve of the first channel, and separately translate transmission characteristic curves of the other channels in an amplitude direction by second distances corresponding to the transmission characteristic curves of the channels, to make amplitudes corresponding to same frequencies on the transmission characteristic curves of the two adjacent channels overlapped, so as to form one continuous curve.



    [0082] In specific implementation, if there are multiple same frequencies on the transmission characteristic curves of the at least two channels, the processor 802 is specifically configured to:

    calculate differences between amplitudes corresponding to all the same frequencies on the transmission characteristic curves of the adjacent channels; and

    calculate an average value of the differences between the amplitudes corresponding to all the same frequencies, and use the average value as the first distance MovedV.



    [0083] Optionally, if a transmission characteristic curve of a channel cannot be directly collected in a network, the interface circuit 801 is specifically configured to:

    collect pre-equalization coefficients of the at least two channels in the cable modem; and

    obtain the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels.



    [0084] It should be noted that the obtained transmission characteristic curve of the to-be-measured frequency band in this case is a relative value of a transmission characteristic, not an absolute value. That is, a location corresponding to each frequency on the curve can reflect a transmission characteristic of a channel. According to a shape of the curve, quality of the channel can be analyzed, and fault diagnosis and locating, line adjustment, and the like can be performed. However, an amplitude of the curve is not an actual receive level. To obtain an absolute value of the transmission characteristic of the to-be-measured frequency band, optionally, the interface circuit 801 may be further configured to:
    collect transmit power of the cable modem and receive power of a cable modem termination system that are corresponding to each of the channels.

    [0085] The processor 802 may be further configured to:

    obtain line attenuation power according to the transmit power and the receive power corresponding to each of the channels; and

    shift upward the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain the absolute value of the transmission characteristic of the frequency band.



    [0086] The server in this embodiment may be configured to execute the technical solutions in FIG. 2 and the foregoing method embodiment. Implementation principles of the server and the method embodiment are similar. Functions of each function module of the server may be specifically implemented according to the method in the foregoing method embodiment. For a specific implementation process thereof, refer to related description in the foregoing embodiment, and details are not described herein.

    [0087] According to the server in this embodiment, an interface circuit 801 obtains a transmission characteristic curve of each channel on a to-be-measured frequency band in a CM, and a processor 802 obtains a transmission characteristic curve of the entire to-be-measured frequency band in a curve translation manner. Because a data collection process and a data processing process can be performed when an HFC network is in a working state, the transmission characteristic curve of the to-be-measured frequency band can be obtained when the HFC network is in a working state. In addition, a manner of collecting a pre-equalization coefficient of a channel or directly collecting in-band frequency response data of a channel is used instead of a manner of measuring a signal by using an external instrument, and there is no impact caused by noise during instrument measurement. Therefore, compared with a transmission characteristic curve obtained by using a spectrum analyzer or a network analyzer in the prior art, the transmission characteristic curve obtained in this embodiment of the present invention has higher accuracy.

    [0088] Persons of ordinary skill in the art may understand that all or some of the steps of the method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer readable storage medium. When the program runs, the steps of the method embodiments are performed. The foregoing storage medium includes: any medium that can store program code, such as a ROM, a RAM, a magnetic disk, or an optical disc.

    [0089] Finally, it should be noted that the foregoing embodiments are merely intended for describing the technical solutions of the present invention, but not for limiting the present invention. Although the present invention is described in detail with reference to the foregoing embodiments, persons of ordinary skill in the art should understand that they may still make modifications to the technical solutions described in the foregoing embodiments or make equivalent replacements to some or all technical features thereof, without departing from the scope of the technical solutions of the embodiments of the present invention.


    Claims

    1. A channel transmission characteristic obtaining method, comprising:

    obtaining (201) transmission characteristic curves of at least two channels from a cable modem to a cable modem termination system of a hybrid fiber-coaxial, HFC, network in a channel scanning manner, wherein one characteristic curve reflects amplitudes of one channel at all frequencies, the at least two channels form one contiguous frequency band, and frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude;

    translating (202) the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve; and

    using (203) the continuous curve as a transmission characteristic curve of the contiguous frequency band;

    characterized in that the translating the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve comprises:

    calculating differences between amplitudes corresponding to all the same frequencies on transmission characteristic curves of any two adjacent channels;

    if the two adjacent channels have only one overlapped frequency, using the difference between amplitudes corresponding to the one overlapped frequency as a first distance MovedV;

    if there are multiple same frequencies on the transmission characteristic curves of the two adjacent channels, calculating an average value of the differences between the amplitudes corresponding to all the same frequencies, and using the average value as the first distance MovedV;

    fixing a transmission characteristic curve of one channel in the any two adjacent channels, and translating a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band comprising the two adjacent channels; and

    continuing to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band comprising the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.


     
    2. The method according to claim 1, wherein the fixing a transmission characteristic curve of one channel in the any two adjacent channels comprises: fixing a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels.
     
    3. The method according to any one of claims 1 to 2, wherein the obtaining transmission characteristic curves of at least two channels from a cable modem to a cable modem termination system of the HFC network comprises:

    collecting pre-equalization coefficients of the at least two channels of the cable modem of the HFC network; and

    obtaining the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels.


     
    4. The method according to any one of claims 1 to 3, wherein the method further comprises:

    collecting (204) transmit power of the cable modem of the HFC network and receive power of the cable modem termination system of the HFC network that are corresponding to each of the channels;

    obtaining (205) line attenuation power according to the transmit power and the receive power corresponding to each of the channels; and

    shifting upward (206) the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain an absolute value of a transmission characteristic of the frequency band.


     
    5. A channel transmission characteristic obtaining apparatus (700), comprising:

    an obtaining module (701), configured to obtain transmission characteristic curves of at least two channels from a cable modem to a cable modem termination system of a hybrid fiber-coaxial, HFC, network in a channel scanning manner, wherein one characteristic curve reflects amplitudes of one channel at all frequencies, the at least two channels form one contiguous frequency band, and frequencies corresponding to the transmission characteristic curves of the at least two channels have frequency values on a same order of magnitude, and have amplitude values on a same order of magnitude; and

    a processing module (702), configured to translate the transmission characteristic curves of the channels in an amplitude direction, to make amplitudes corresponding to same frequencies on all transmission characteristic curves overlapped, so as to form one continuous curve; and use the continuous curve as a transmission characteristic curve of the contiguous frequency band;

    characterized in that the processing module (702) is specifically configured to:

    calculate differences between amplitudes corresponding to all the same frequencies on transmission characteristic curves of any two adjacent channels;

    if the two adjacent channels have only one overlapped frequency, use the difference between amplitudes corresponding to the one overlapped frequency as a first distance MovedV;

    if there are multiple same frequencies on the transmission characteristic curves of the at least two adjacent channels, calculate an average value of the differences between the amplitudes corresponding to all the same frequencies, and use the average value as the first distance MovedV;

    fix a transmission characteristic curve of one channel in the any two adjacent channels, and translate a transmission characteristic curve of the other channel in an amplitude direction by the first distance MovedV, to make the amplitudes corresponding to the same frequency on the transmission characteristic curves of the two adjacent channels overlapped, so as to form a transmission characteristic curve corresponding to a frequency band comprising the two adjacent channels; and

    continue to execute the foregoing steps for the transmission characteristic curve corresponding to the frequency band comprising the adjacent channels, until transmission characteristic curves corresponding to all channels form one continuous curve.


     
    6. The apparatus according to claim 5, wherein the processing module (702) is specifically configured to:
    fix a transmission characteristic curve of a channel that has a smaller frequency in the any two adjacent channels.
     
    7. The apparatus according to any one of claims 5 to 6, wherein the obtaining module (701) is specifically configured to:

    collect pre-equalization coefficients of the at least two channels of the cable modem of the HFC network; and

    obtain the transmission characteristic curves of the channels according to the pre-equalization coefficients of the at least two channels.


     
    8. The apparatus according to any one of claims 5 to 7, wherein the obtaining module (701) is further configured to:

    collect transmit power of the cable modem of the HFC network and receive power of the cable modem termination system of the HFC network that are corresponding to each of the channels; and

    the processing module (702) is further configured to:

    obtain line attenuation power according to the transmit power and the receive power corresponding to each of the channels; and

    shift upward the transmission characteristic curve of the frequency band in an amplitude direction by a value of the line attenuation power, to obtain an absolute value of a transmission characteristic of the frequency band.


     
    9. The apparatus (700) according to any one of claims 5 to 8, wherein the apparatus (700) is a server (800) disposed on a network side, comprising:

    an interface circuit (801), configured as the obtaining module (701); and

    a processor (802), configured as the processing module (702).


     


    Ansprüche

    1. Verfahren zur Erfassung von Merkmalen eines Übertragungskanals, umfassend:

    Erfassen (201) von Übertragungsmerkmalskurven von mindestens zwei Kanälen von einem Kabelmodem zu einem Kabelmodemanschlusssystem eines hybriden Faserkoaxialkabel(HFC)-Netzwerks in einer Kanalabtastungsweise, wobei eine Merkmalskurve Amplituden eines Kanals bei allen Frequenzen widerspiegelt, die mindestens zwei Kanäle ein zusammenhängendes Frequenzband bilden und Frequenzen, die den Übertragungsmerkmalskurven der mindestens zwei Kanäle entsprechen, Frequenzwerte in der gleichen Größenordnung aufweisen und Amplitudenwerte in der gleichen Größenordnung aufweisen;

    Verschieben (202) der Übertragungsmerkmalskurven der Kanäle in einer Amplitudenrichtung, um Amplituden, die auf allen Übertragungsmerkmalskurven den gleichen Frequenzen entsprechen, überlappen zu lassen, um so eine kontinuierliche Kurve zu bilden; und

    Verwenden (203) der kontinuierlichen Kurve als eine Übertragungsmerkmalskurve des benachbarten Frequenzbandes;

    dadurch gekennzeichnet, dass das Verschieben der Übertragungsmerkmalskurven der Kanäle in einer Amplitudenrichtung, um Amplituden, die auf allen Übertragungsmerkmalskurven den gleichen Frequenzen entsprechen, überlappen zu lassen, um so eine kontinuierliche Kurve zu bilden, umfasst:

    Berechnen von Differenzen zwischen Amplituden, die auf allen Übertragungsmerkmalskurven von zwei beliebigen benachbarten Kanälen den gleichen Frequenzen entsprechen;

    wenn die zwei benachbarten Kanäle nur eine überlappende Frequenz aufweisen, Verwenden der Differenz zwischen Amplituden, die der einen überlappten Frequenz entsprechen, als einen ersten Abstand MovedV;

    wenn auf den Übertragungsmerkmalskurven der zwei benachbarten Kanäle mehrere gleiche Frequenzen vorhanden sind, Berechnen eines Durchschnittswerts der Differenzen zwischen den Amplituden, die allen den gleichen Frequenzen entsprechen, und Verwenden des Durchschnittswerts als den ersten Abstand MovedV;

    Festsetzen einer Übertragungsmerkmalskurve eines Kanals in den beliebigen zwei benachbarten Kanälen und Verschieben einer Übertragungsmerkmalskurve des anderen Kanals in einer Amplitudenrichtung um den ersten Abstand MovedV, um die Amplituden, die auf den Übertragungsmerkmalskurven der zwei benachbarten Kanäle den gleichen Frequenzen entsprechen, überlappen zu lassen, um eine Übertragungsmerkmalskurve zu bilden, die einem Frequenzband entspricht, das die zwei benachbarten Kanäle umfasst; und

    Fortsetzen der Ausführung der vorhergehenden Schritte für die Übertragungsmerkmalskurve, die dem Frequenzband entspricht, das die benachbarten Kanäle umfasst, bis die allen Kanälen entsprechenden Übertragungsmerkmalskurven eine kontinuierliche Kurve bilden.


     
    2. Verfahren nach Anspruch 1, wobei das Festsetzen einer Übertragungsmerkmalskurve eines Kanals in den beliebigen zwei benachbarten Kanälen umfasst: Festsetzen einer Übertragungsmerkmalskurve eines Kanals, der in den beliebigen zwei benachbarten Kanälen eine kleinere Frequenz aufweist.
     
    3. Verfahren nach einem der Ansprüche 1 bis 2, wobei das Erfassen der Übertragungsmerkmalskurven von mindestens zwei Kanälen von einem Kabelmodem zu einem Kabelmodemanschlusssystem des HFC-Netzwerks umfasst:

    Sammeln von Vorverzerrungskoeffizienten der mindestens zwei Kanäle des Kabelmodems des HFC-Netzwerks; und

    Erfassen der Übertragungsmerkmalskurven der Kanäle gemäß den Vorverzerrungskoeffizienten der mindestens zwei Kanäle.


     
    4. Verfahren nach einem der Ansprüche 1 bis 3, wobei das Verfahren ferner umfasst:

    Sammeln (204) der Übertragungsleistung des Kabelmodems des HFC-Netzwerks und der Empfangsleistung des Kabelmodemanschlusssystems des HFC-Netzwerks, die jedem der Kanäle entsprechen;

    Erfassen (205) einer Leitungsdämpfungsleistung gemäß der Übertragungsleistung und der Empfangsleistung, die jedem der Kanäle entsprechen; und

    Aufwärtsverschieben (206) der Übertragungsmerkmalskurve des Frequenzbandes in einer Amplitudenrichtung um einen Wert der Leitungsdämpfungsleistung, um einen Absolutwert eines Übertragungsmerkmals des Frequenzbandes zu erhalten.


     
    5. Vorrichtung zur Erfassung von Merkmalen eines Übertragungskanals (700), umfassend: ein Erfassungsmodul (701), das konfiguriert ist, um Übertragungsmerkmalskurven von mindestens zwei Kanälen von einem Kabelmodem zu einem Kabelmodemanschlusssystem eines hybriden Faserkoaxialkabel(HFC)-Netzwerks in einer Kanalabtastungsweise zu erfassen, wobei eine Merkmalskurve Amplituden eines Kanals bei allen Frequenzen widerspiegelt, die mindestens zwei Kanäle ein zusammenhängendes Frequenzband bilden und Frequenzen, die den Übertragungsmerkmalskurven der mindestens zwei Kanäle entsprechen, Frequenzwerte in der gleichen Größenordnung aufweisen und Amplitudenwerte in der gleichen Größenordnung aufweisen; und
    ein Verarbeitungsmodul (702), das konfiguriert ist, um die Übertragungsmerkmalskurven der Kanäle in einer Amplitudenrichtung zu verschieben, um Amplituden, die auf allen Übertragungsmerkmalskurven den gleichen Frequenzen entsprechen, überlappen zu lassen, um so eine kontinuierliche Kurve zu bilden; und die kontinuierliche Kurve als eine Übertragungsmerkmalskurve des benachbarten Frequenzbandes zu verwenden;
    dadurch gekennzeichnet, dass das Verarbeitungsmodul (702) insbesondere konfiguriert ist, um:

    Differenzen zwischen Amplituden zu berechnen, die auf allen Übertragungsmerkmalskurven von zwei beliebigen benachbarten Kanälen den gleichen Frequenzen entsprechen;

    wenn die zwei benachbarten Kanäle nur eine überlappende Frequenz aufweisen, die Differenz zwischen Amplituden, die der einen überlappten Frequenz entsprechen, als einen ersten Abstand MovedV zu verwenden;

    wenn auf den Übertragungsmerkmalskurven der zwei benachbarten Kanäle mehrere gleiche Frequenzen vorhanden sind, einen Durchschnittswert der Differenzen zwischen den Amplituden zu berechnen, die allen den gleichen Frequenzen entsprechen, und den Durchschnittswert als den ersten Abstand MovedV zu verwenden;

    eine Übertragungsmerkmalskurve eines Kanals in den beliebigen zwei benachbarten Kanälen festzusetzen und eine Übertragungsmerkmalskurve des anderen Kanals in einer Amplitudenrichtung um den ersten Abstand MovedV zu verschieben, um die Amplituden, die auf den Übertragungsmerkmalskurven der zwei benachbarten Kanäle den gleichen Frequenzen entsprechen, überlappen zu lassen, um eine Übertragungsmerkmalskurve zu bilden, die einem Frequenzband entspricht, das die zwei benachbarten Kanäle umfasst; und

    die Ausführung der vorhergehenden Schritte für die Übertragungsmerkmalskurve fortzusetzen, die dem Frequenzband entspricht, das die benachbarten Kanäle umfasst, bis die allen Kanälen entsprechenden Übertragungsmerkmalskurven eine kontinuierliche Kurve bilden.


     
    6. Vorrichtung nach Anspruch 5, wobei das Verarbeitungsmodul (702) insbesondere konfiguriert ist, um:
    eine Übertragungsmerkmalskurve eines Kanals festzusetzen, der in den zwei benachbarten Kanälen eine kleinere Frequenz aufweist.
     
    7. Vorrichtung nach einem der Ansprüche 5 bis 6, wobei das Erfassungsmodul (701) insbesondere konfiguriert ist, um:

    die Vorverzerrungskoeffizienten der mindestens zwei Kanäle des Kabelmodems des HFC-Netzwerks zu sammeln; und

    die Übertragungsmerkmalskurven der Kanäle gemäß den Vorverzerrungskoeffizienten der mindestens zwei Kanäle zu erfassen.


     
    8. Vorrichtung nach einem der Ansprüche 5 bis 7, wobei das Erfassungsmodul (701) ferner konfiguriert ist, um:

    die Übertragungsleistung des Kabelmodems des HFC-Netzwerks und die Empfangsleistung des Kabelmodemanschlusssystems des HFC-Netzwerks zu sammeln, die jedem der Kanäle entsprechen; und

    das Verarbeitungsmodul (702) ferner konfiguriert ist, um:

    eine Leitungsdämpfungsleistung gemäß der Übertragungsleistung und der Empfangsleistung zu erfassen, die jedem der Kanäle entsprechen; und

    die Übertragungsmerkmalskurve des Frequenzbandes in einer Amplitudenrichtung um einen Wert der Leitungsdämpfungsleistung aufwärts zu verschieben, um einen Absolutwert eines Übertragungsmerkmals des Frequenzbandes zu erfassen.


     
    9. Vorrichtung (700) nach einem der Ansprüche 5 bis 8, wobei die Vorrichtung (700) ein auf der Netzwerkseite angeordneter Server (800) ist, umfassend:

    eine Schnittstellenschaltung (801), die als das Erfassungsmodul (701) konfiguriert ist; und

    einen Prozessor (802), der als das Verarbeitungsmodul (702) konfiguriert ist.


     


    Revendications

    1. Procédé d'obtention des caractéristiques de transmission d'un canal, comprenant :

    l'obtention (201) de courbes caractéristiques de transmission d'au moins deux canaux d'un modem à câble à un système de terminaison de modem à câble d'un réseau hybride fibre-coaxial, HFC, en mode de balayage de canal, dans lequel une courbe caractéristique reflète les amplitudes d'un canal à toutes les fréquences, les au moins deux canaux forment une bande de fréquence contiguë et les fréquences correspondant aux courbes caractéristiques de transmission des au moins deux canaux ont des valeurs de fréquence du même ordre de grandeur et des valeurs d'amplitude du même ordre de grandeur ;

    la translation (202) des courbes caractéristiques de transmission des canaux dans une direction de l'amplitude, pour superposer les amplitudes correspondant aux mêmes fréquences sur toutes les courbes caractéristiques de transmission, de manière à former une courbe continue ; et

    l'utilisation (203) de la courbe continue en tant que courbe caractéristique de transmission de la bande de fréquences contiguës ;

    caractérisé en ce que la translation des courbes caractéristiques de transmission des canaux dans une direction de l'amplitude, pour superposer les amplitudes correspondant aux mêmes fréquences sur toutes les courbes caractéristiques de transmission, de manière à former une courbe continue, comprend :

    le calcul des différences entre les amplitudes correspondant à toutes les mêmes fréquences sur les courbes caractéristiques de transmission de deux canaux adjacents quelconques ;

    si les deux canaux adjacents n'ont qu'une seule fréquence superposée, l'utilisation de la différence entre les amplitudes correspondant à la fréquence superposée comme première distance MovedV ;

    s'il existe plusieurs fréquences égales sur les courbes caractéristiques de transmission des deux canaux adjacents, le calcul d'une valeur moyenne des différences entre les amplitudes correspondant à toutes fréquences égales, et l'utilisation de la valeur moyenne comme première distance MovedV ;

    la fixation d'une courbe caractéristique de transmission d'un canal de deux canaux adjacents quelconques, et la translation d'une courbe caractéristique de transmission de l'autre canal dans une direction de l'amplitude de la première distance MovedV, pour superposer les amplitudes correspondant à la même fréquence sur les courbes caractéristiques de transmission des deux canaux adjacents, de manière à former une courbe caractéristique de transmission correspondant à une bande de fréquence comprenant les deux canaux adjacents ; et

    la continuation de l'exécution des étapes précédentes pour la courbe caractéristique de transmission correspondant à la bande de fréquences comprenant les canaux adjacents, jusqu'à ce que les courbes caractéristiques de transmission correspondant à tous les canaux forment une courbe continue.


     
    2. Procédé selon la revendication 1, dans lequel la fixation d'une courbe caractéristique de transmission d'un canal dans l'un quelconque des deux canaux adjacents comprend : la fixation d'une courbe caractéristique de transmission d'un canal ayant une fréquence plus faible dans deux canaux adjacents quelconques.
     
    3. Procédé selon l'une quelconque des revendications 1 à 2, dans lequel l'obtention de courbes caractéristiques de transmission d'au moins deux canaux d'un modem à câble à un système de terminaison de modem à câble d'un réseau HFC comprend :

    la collecte des coefficients de pré-égalisation des au moins deux canaux du modem à câble du réseau HFC ; et

    l'obtention des courbes caractéristiques de transmission des canaux en fonction des coefficients de pré-égalisation des au moins deux canaux.


     
    4. Procédé selon l'une quelconque des revendications 1 à 3, dans lequel le procédé comprend en outre :

    la collecte (204) de la puissance d'émission du modem à câble du réseau HFC et de la puissance de réception du système de terminaison de modem à câble du réseau HFC qui correspondent à chacun des canaux ;

    l'obtention (205) d'une puissance d'atténuation de ligne en fonction de la puissance d'émission et de la puissance de réception correspondant à chacun des canaux ; et

    le déplacement vers le haut (206) de la courbe caractéristique de transmission de la bande de fréquence dans une direction d'amplitude d'une valeur de la puissance d'atténuation de ligne, pour obtenir une valeur absolue d'une caractéristique de transmission de la bande de fréquence.


     
    5. Appareil (700) d'obtention des caractéristiques de transmission d'un canal, comprenant :

    un module d'obtention (701), configuré pour obtenir des courbes caractéristiques de transmission d'au moins deux canaux d'un modem à câble à un système de terminaison de modem à câble d'un réseau hybride fibre-coaxial, HFC, en mode de balayage de canal, dans lequel une courbe caractéristique reflète les amplitudes d'un canal à toutes les fréquences, les au moins deux canaux forment une bande de fréquence contiguë et les fréquences correspondant aux courbes caractéristiques de transmission des au moins deux canaux ont des valeurs de fréquence du même ordre de grandeur et des valeurs d'amplitude du même ordre de grandeur ; et

    un module de traitement (702), configuré pour effectuer la translation des courbes caractéristiques de transmission des canaux dans une direction de l'amplitude, de façon à superposer les amplitudes correspondant aux mêmes fréquences sur toutes les courbes caractéristiques de transmission, de manière à former une courbe continue ;

    et utiliser la courbe continue comme courbe caractéristique de transmission de la bande de fréquences contiguës ;

    caractérisé en ce que le module de traitement (702) est spécifiquement configuré pour :

    calculer des différences entre les amplitudes correspondant à toutes les mêmes fréquences sur les courbes caractéristiques de transmission de deux canaux adjacents quelconques ;

    si les deux canaux adjacents n'ont qu'une seule fréquence superposée, utiliser la différence entre les amplitudes correspondant à la fréquence superposée comme première distance MovedV ;

    s'il existe plusieurs fréquences égales sur les courbes caractéristiques de transmission des deux canaux adjacents, calculer une valeur moyenne des différences entre les amplitudes correspondant à toutes les fréquences égales, et utiliser la valeur moyenne comme première distance MovedV ;

    fixer une courbe caractéristique de transmission d'un canal dans deux canaux adjacents quelconques, et effectuer la translation d'une courbe caractéristique de transmission de l'autre canal dans une direction de l'amplitude de la première distance MovedV, pour superposer les amplitudes correspondant à la même fréquence sur les courbes caractéristiques de transmission des deux canaux adjacents, de manière à former une courbe caractéristique de transmission correspondant à une bande de fréquence comprenant les deux canaux adjacents ; et

    continuer l'exécution des étapes précédentes pour la courbe caractéristique de transmission correspondant à la bande de fréquences comprenant les canaux adjacents, jusqu'à ce que les courbes caractéristiques de transmission correspondant à tous les canaux forment une courbe continue.


     
    6. Appareil selon la revendication 5, dans lequel le module de traitement (702) est spécifiquement configuré pour :
    fixer une courbe caractéristique de transmission d'un canal ayant une fréquence plus faible dans deux canaux adjacents quelconques.
     
    7. Appareil selon l'une quelconque des revendications 5 à 6, dans lequel le module d'obtention (701) est spécifiquement configuré pour :

    recueillir les coefficients de pré-égalisation des au moins deux canaux du modem à câble du réseau HFC ; et

    obtenir les courbes caractéristiques de transmission des canaux en fonction des coefficients de pré-égalisation des au moins deux canaux.


     
    8. Appareil selon l'une quelconque des revendications 5 à 7, dans lequel le module d'obtention (701) est en outre configuré pour :

    recueillir la puissance d'émission du modem à câble du réseau HFC et la puissance de réception du système de terminaison de modem à câble du réseau HFC qui correspondent à chacun des canaux ; et

    dans lequel le module de traitement (702) est en outre configuré pour :

    obtenir une puissance d'atténuation de ligne en fonction de la puissance d'émission et de la puissance de réception correspondant à chacun des canaux ; et

    déplacer vers le haut la courbe caractéristique de transmission de la bande de fréquence dans une direction d'amplitude d'une valeur de la puissance d'atténuation de ligne, pour obtenir une valeur absolue d'une caractéristique de transmission de la bande de fréquence.


     
    9. Appareil (700) selon l'une quelconque des revendications 5 à 8, dans lequel l'appareil (700) est un serveur (800) disposé côté réseau, comprenant :
    un circuit d'interface (801), configuré comme module d'obtention (701) ; et un processeur (802), configuré comme module de traitement (702).
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description