SYSTEM AND METHOD FOR ADJUSTING DIGITAL SUBSCRIBER LINE BASED SERVICES
A system and method for adjusting digital subscriber line based services is provided. In a particular embodiment, a computer readable medium is provided including computer-executable instructions that when executed, cause a computer to modify a value of a first control parameter associated with a Digital Subscriber Line (DSL) network based on a first performance parameter that is measured in real-time at a DSL modem over a first pre-determined time period.
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The present application claims priority from and is a continuation of patent application Ser. No. 10/958,631 filed on Oct. 5, 2004 and entitled “System and Method for Optimizing Digital Subscriber Line Based Services,” the contents of which are expressly incorporated herein by reference in their entirety.
FIELD OF THE DISCLOSUREThe present disclosure relates generally to adjusting digital subscriber line based services.
BACKGROUNDDigital subscriber line (DSL) has quickly emerged as a high quality solution for high speed Internet access and other services associated with high speed Internet services, such as, voice over Internet protocol (VoIP) and streaming video services. DSL can transmit both voice and data simultaneously over an existing, single copper pair up to 18,000 feet long. Since DSL can utilize existing copper telephone lines, the service costs associated with DSL is relatively low for service providers and for customers. Moreover, since data can be transmitted relatively quickly using DSL, it is a very attractive option for providing high-speed access to end users.
Traditional plain old telephone service (POTS) uses a narrow 4-kHz baseband frequency to transmit analog voice signals, and current modem technology can achieve a data transmission rate of up to 56 kb/s. DSL, e.g., asymmetric DSL (ADSL), can increase the usable frequency range from 4 kHz to 1.1 MHz and can provide a data transmission rate up to 8 Mb/s. Further, frequency division multiplexing (FDM) can allow ADSL to create multiple frequency bands that can be used to carry data simultaneously with POTS signals over the same copper pair. The lower 4-kHz frequency range is reserved for POTS, the middle frequency band is used to transmit upstream data and the larger, higher frequency band is used to transmit downstream data.
Discrete multi-tone (DMT) modulation is the American National Standards Institute (ANSI) standard T1.413 line code. DMT modulation is used to divide the data bandwidth into 256 subchannels, or tones, that range from 20 kHz to 1.1 MHz for ADSL. Upstream data transfer frequencies range from 20 kHz to 160 kHz and downstream data transfer frequencies range from 240 kHz to 1.1 MHz. The remaining tones are used as guard bands for dividing the three frequency bands, and one pilot tone is used in each data stream, both upstream and downstream, for timing purposes. Each tone, or channel, has a spacing of 4.3 kHz and each tone supports a maximum number of 15 bits, which is limited by the signal-to-noise ratio on the channel. Since the tones in the higher frequencies are subject to higher attenuation and noise, the number of bits per tone can be fewer than that in the lower frequencies.
In addition to the normal data bits, an embedded operations channel (EOC) is provided as part of the ADSL protocol for communication between the ATU-C and the ATU-R to provide in-service and out-of-service maintenance, to retrieve a limited amount of ATU-R status information, and to monitor ADSL performance.
Typically, the optimization of the data transmission channels used for DSL data transport, e.g., VoIP and video, is largely ignored due to technical and economic factors. Without optimization, DSL circuits are either over-engineered or under-engineered for performance. Over engineered circuits operate at sub-optimum rates and deliver less performance to the customer. Under-engineered circuits experience frequent data errors that result in increased peer-to-peer communications required to perform re-transmissions of data packets. This yields a reduced throughput to the customer. Some under-engineered circuits experience error rates severe enough to cause service interruption or the inability to establish the data channel when initially requested by the customer.
Accordingly, there is a need for a system and method for adjusting digital subscriber line based services.
The present invention is pointed out with particularity in the appended claims. However, other features are described in the following detailed description in conjunction with the accompanying drawings in which:
In a particular embodiment, a computer readable medium is provided, and includes computer-executable instructions that when executed, cause a computer to modify a value of a first control parameter associated with a Digital Subscriber Line (DSL) network based on a first performance parameter that is measured in real-time at a DSL modem over a first pre-determined time period.
In another particular embodiment, a method of modifying a Digital Subscriber Line (DSL) network is provided. The method includes adjusting a control parameter value associated with the DSL network based at least in part on a performance parameter associated with a DSL circuit of the DSL network. The performance parameter is measured in real-time at a DSL modem over a predetermined period of time.
In another particular embodiment, a Digital Subscriber Line (DSL) network is provided and includes a computer adapted to execute a computer program to modify a control parameter associated with a DSL channel of the DSL network. The control parameter modification is based at least in part on a performance parameter associated with the DSL network. The performance parameter is measured in real-time at a DSL device over a predetermined time period.
In another particular embodiment, a method is provided that can be used for modifying a control parameter associated with a Digital Subscriber Line (DSL) service. Initially, a real-time performance parameter is received from a first termination unit that is coupled to a DSL circuit. The real-time performance parameter can be measured at the termination unit after the termination unit is provisioned and after the DSL circuit is placed in-service. In a particular embodiment, a value of a control parameter associated with the DSL circuit can be modified based on the measured real-time performance parameter.
In another particular embodiment, activity over the DSL circuit is monitored in real-time. Further, a determination is made to ascertain when usage of the DSL circuit is below a threshold. The provisionable service parameter corresponding to the control parameter can be modified when the usage is below the threshold. In still another particular embodiment, a first re-provisioning cycle between a first termination unit and a second termination unit coupled to the DSL circuit can be initiated using the provisionable service parameter. In yet another particular embodiment, the first termination device is a DSL modem and the second termination device is a DSL modem.
Also, in another particular embodiment, a determination is made in order to determine whether operation of the DSL circuit is within an acceptable operating range. The provisionable service parameter is modified after determining that the operation of the DSL circuit is not within the acceptable operating range. Further, performance data of the termination unit is monitored and a determination is made in order to ascertain whether operation of the DSL circuit is stable based on the monitored performance data.
In another embodiment, a digital subscriber line (DSL) network is provided and includes a first modem at a central office and a second modem at a remote site. A DSL channel is established between the first modem and the second modem. Further, a computer communicates with the first modem and the second modem. The computer includes a program for modifying a provisionable service parameter associated with the DSL channel based on measured in-service performance parameters received from the first modem or the second modem.
In yet another embodiment, a method for modifying a data network is provided and includes provisioning a data circuit within the data network with a first set of provisioning parameters. Thereafter, a first set of in-service performance data is acquired from a terminating unit coupled to the data circuit. A second set of provisioning parameters is determined based on the first set of performance data. The data circuit can be re-provisioned with the second set of provisioning parameters.
Referring to
In an illustrative embodiment, a layer 2/layer 3 switch 110 is connected to the first DSL MODEM 106 and a router 112 is connected to the second DSL MODEM 108. In a particular embodiment, the layer 2/layer 3 switch 100 is an asynchronous transfer mode (ATM) switch or an Ethernet switch. As shown, the layer 2/layer 3 switch 110 and the router 112 are connected to a data network 114, e.g., the Internet. As such, in a particular embodiment, the layer 2/layer 3 switch 110 and the router 112 provide data network connectivity to the first DSL MODEM 106 and the second DSL MODEM 108. In an illustrative embodiment, an Internet service provider (ISP) 116 is connected to the data network 114. Moreover, a corporate network 118 is connected to the data network 114. For simplicity, only one ISP 116 and only one corporate network 118 is shown connected to the data network 114, but any number of ISPs and any number of corporate networks 118 can be connected to the data network 114.
As depicted in
In a particular embodiment, data can be transmitted over the DSL network 100 using transmission control protocol/Internet protocol (TCP/IP), file transfer protocol (FTP) (e.g., for large files), user datagram protocol (UDP) (e.g., for VoIP and streaming video), or real-time transport protocol (RTP) (e.g., for streaming video files or streaming audio files). As such, the protocol used is an indirect user of the physical layer of the DSL network 100. In order to provide peak DSL service, and peak protocol throughput, using the DSL network 100, the physical layer of the DSL network 100 can have its performance enhanced or optimized. In other words, the circuits in the DSL network 100 that are established between the CO 102 and the customer residence 128 can be enhanced or optimized. Optimization is a process of finding and establishing optimal values for provisionable data communications parameters. Once a circuit is optimized, it can provide optimum or near optimum DSL service regardless of the operating conditions.
In an illustrative embodiment, DSL performance is dominated by two major factors: 1) insertion loss caused by the transmission cable connecting the DSL modems; and 2) electronic noise that reduces the signal to noise ratio at the modem receivers. The electronic noise generally includes a relatively predictable amount of random noise and intermittent noise known as impulse noise. Construction and service records can provide information about the transmission channel loop from which the insertion loss can be ascertained. However, both components of the noise on the channel are unknown. Typically, a service provider does not measure the noise on its circuits before a sale is made to a customer, nor does the service provider typically have accurate information about expected or anticipated noise levels on the data communication circuit that will be used by a customer. Loss and noise could be measured prior to circuit provisioning, but the costs associated with such a project could be overly expensive.
In a particular embodiment, the information necessary to enhance or optimize the circuits in the DSL network 100 is available, but only after the circuits have been provisioned, service has been activated, and after the service is in use by one or more customers.
Referring now to
At block 200, an DSL circuit, i.e., a connection between one of the DSL modems 106, 108 (
In a particular embodiment, to optimize the portion of the DSL circuit transmitting data to a user computer, each of these measurements may be measured by an DSL modem at a user residence. Also, in a particular embodiment, the measurements may be taken by a DSL modem at the CO 102 (
Proceeding to block 204, the performance parameters measured in step 202 are analyzed in order to make a number of determinations. In an illustrative embodiment, the maximum attainable bit rate is determined, e.g., by a reported value from the ATU-C or the ATU-R. Moreover, the loop length can be estimated based in part on the HLOG[n] values for the upstream portion of the DSL channel. In a particular embodiment, excessive power levels can be detected. Further, any cross talk, any white noise, and any non-linear echoes can be detected based on patterns observed in the empirical data collected per tone. For example, cross talk can be determined in part based on the QLN[n] values measured above. In a particular embodiment, the source of white noise or cross talk can be determined based on the “finger prints” of the different sources of the white noise. The “finger prints” of the sources of the white noise can be empirically determined and can include carrier tones or frequencies associated with the sources of the white noise or cross talk. The sources of the white noise or cross talk can include, for example, amplitude modulation (AM) radio interference, HAM radio interference, ionosphere interference that can depend on a time of day, and T-carrier interference.
In a particular embodiment, the presence and location of bridged taps, the presence of bad splices, the presence of bad grounds, and the presence of bad bonds can be determined based in part on the values of the performance parameters measured above. Additionally, an inadequately filtered inside wire at a customer location, the presence of a maintenance test unit, and the presence of an alarm system on an DSL line can be determined based in part on the values performance parameters measured above.
At block 206, one or more of the control parameters, shown in Table 2, are automatically adjusted to account for any observed deficiencies based on the collected values of the performance parameters. For example, in a particular embodiment, the data rates can be adjusted to maximize service performance. Power and noise margin settings can be adjusted. PSD masks are adjusted to limit cross talk on the DSL channel. Further, the forward error correction (FEC) controls and interleaved settings can be adjusted to optimize TCP/IP performance and minimize signal latency in the presence of impulse noise. Proceeding to block 208, the existences of any physical problems that may require the attention of service person are indicated, e.g., to the customer or a service person. The physical problems can include one or more bridged taps, one or bad wire bonds, one or more bad grounds, one or more bad splices, one or more line filtering problems, and may require the attention of a service person in order to correct the problem.
Moving to block 210, layer 2 and layer 3 activity on the DSL circuit is monitored in real-time. (Layer 2 and layer 3 are based on the OSI seven-layer model of networking.) At step 212, a decision is made in order to determine when usage of the DSL circuit is at a minimum. If the usage is not at a minimum, the logic returns to block 210 and the activity on the DSL circuit continues to be monitored. On the other hand, when the usage is at a minimum, the logic proceeds to block 214 and communication is established between the ATU-C and the ATU-R. At block 216, the line provisioning parameters are modified based on the data collected and analyzed above. In a particular embodiment, the line provision parameters are modified based on the adjusted control parameters. Moving to block 218, a re-training cycle is forced between the ATU-R and the ATU-C. Then, the ATU-R and the ATU-C are monitored in real-time, at block 220. Proceeding to step 222, a determination is made in order to ascertain whether service over the DSL circuit is restored. If service is not restored, the logic returns to block 218 and another re-training cycle is forced between the ATU-C and the ATU-R and continues as previously described. If service is restored, the logic continues to step 224.
At step 224, a decision is made in order to determine whether operation of the DSL circuit is within a normal operating range. If the operation is not within the normal operating range, the logic returns to block 218 and continues as previously described. Conversely, if the operation of the ADLS circuit is within the normal operating range, the logic moves to block 226 where the ATU-R and the ATU-C are monitored. Specifically, in a particular embodiment, performance data for the ATU-R and the ATU-C is monitored. At step 228, a determination is made in order to determine if the operation of the DSL circuit is stable. If not, the logic returns to step 200 and the DSL circuit is re-optimized using the steps previously described. If the operation of the DSL circuit is stable, the logic ends at state 230.
In a particular embodiment, the method can be repeated iteratively for each new DSL line until each new DSL line reaches an acceptable state of performance. Moreover, each line can be managed using a state machine translation table that incorporates the performance parameters and control parameters shown in Table 1 and Table 2.
With the configuration of structure described above, the system and method for optimizing DSL data service provides a method to improve and preferably to ensure optimal performance of individual circuits of an DSL network based on numerous parameters measured in real-time. In an illustrative embodiment, each DSL circuit can be optimized many times over the life of the DSL circuit. For example, each DSL circuit can be optimized on a predetermined schedule, e.g., once a week, twice a week, once a month, twice a month, once every two months, once every six months, once a year, etc. Also, the DSL circuit can be monitored and when the operation of the DSL circuit becomes unstable, settings associated with the DSL circuit can be adjusted or modified to bring the operation of DSL circuit into a stable state. Further, the DSL circuit can be optimized when requested by the customer, if the customer believes his or her DSL service is not functioning properly.
In a particular embodiment, the entire process can be encapsulated in a software program that can be executed by a computer connected to the DSL network, e.g., the central office computer 126. The central office computer 126 can interface with the ATU-Cs and the ATU-Rs, or their respective agents, in order to obtain performance data, extract provisioning data, implant provisioning data, and control the circuit provisioning in order to provide optimum performance of each DSL circuit.
The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.
Claims
1. A computer readable medium including computer-executable instructions that when executed, cause a computer to:
- modify a value of a first control parameter associated with a Digital Subscriber Line (DSL) network based on a first performance parameter;
- wherein the first performance parameter is measured in real-time at a DSL modem over a first pre-determined time period.
2. The computer readable medium of claim 1, wherein the first performance parameter data is measured in real-time over the first pre-determined time period to promote statistical confidence in the first performance parameter.
3. The computer readable medium of claim 1, further comprising computer-executable instructions that when executed, cause the computer to:
- modify the value of the first control parameter associated with the DSL network based on a second performance parameter; wherein
- the second performance parameter is measured in real-time at the DSL modem over a second pre-determined time period.
4. The computer readable medium of claim 3, wherein the first pre-determined time period and the second pre-determined time period are substantially the same.
5. The computer readable medium of claim 3, further comprising computer-executable instructions that when executed, cause the computer to modify a value of a second control parameter associated with the DSL network based on the second performance parameter.
6. The computer readable medium of claim 3, wherein the second performance parameter is measured in real-time over the second pre-determined time period to promote statistical confidence in the second performance parameter.
7. The computer readable medium of claim 1, wherein the DSL modem associated with the DSL network is located at a central office, and wherein the first performance parameter is measured at the central office.
8. The computer readable medium of claim 1, wherein the DSL modem associated with the DSL network is located at a residence, and wherein the first performance parameter is measured at the residence.
9. The computer readable medium of claim 1, wherein measured values of the first performance parameter are communicated to a secure website.
10. The computer readable medium of claim 1, wherein measured values of the first performance parameter are communicated to a secure computer via a secure network connection.
11. A method of modifying a Digital Subscriber Line (DSL) network, the method comprising adjusting a control parameter value associated with the DSL network based at least in part on a performance parameter associated with a DSL circuit of the DSL network, wherein the performance parameter is measured in real-time at a DSL modem over a predetermined period of time.
12. The method of claim 11, wherein the performance parameter is measured in real-time over the first pre-determined time period to promote statistical confidence in the performance parameter.
13. The method of claim 11, wherein the performance parameter comprises a measure of layer 2 activity and layer 3 activity on the DSL circuit.
14. The method of claim 11, further comprising:
- determining that usage of the DSL circuit is below a threshold, wherein the determination is based at least partially upon the performance parameter; and
- adjusting the control parameter value in response to the determination.
15. The method of claim 14, further comprising, in response to the determination that the usage of the DSL circuit is below a threshold, initiating a first re-provisioning cycle between a first termination unit coupled to the DSL circuit and a second termination unit coupled to the DSL circuit.
16. The method of claim 15, wherein the first termination unit comprises a first DSL modem situated at a central office and the second termination unit comprises a second DSL modem situated at a residence.
17. The method of claim 11, further comprising:
- determining, based at least in part on the performance parameter, whether operation of the DSL circuit is within an acceptable operating range; and
- modifying the control parameter value after determining that the operation of the DSL circuit is not within the acceptable operating range.
18. A Digital Subscriber Line (DSL) network comprising:
- a computer adapted to execute a computer program to modify a control parameter associated with a DSL channel of the DSL network;
- wherein the control parameter modification is based at least in part on a performance parameter associated with the DSL network;
- wherein the performance parameter is measured in real-time at a DSL device over a predetermined time period.
19. The DSL network of claim 18, wherein the computer is further adapted to analyze measurements of the performance parameter to promote statistical confidence of the performance parameter.
20. The DSL network of claim 18, wherein the control parameter is a forward error correction control parameter.
Type: Application
Filed: May 23, 2008
Publication Date: Sep 11, 2008
Applicant: SBC Knowledge Ventures, LP (Reno, NV)
Inventors: Raghvendra G. Savoor (Walnut Creek, CA), George Keith Cambron (Walnut Creek, CA), John Porter Van Slyke (Lafayette, CA)
Application Number: 12/126,088
International Classification: H04L 12/26 (20060101);