Apparatus and methods for incorporating bandwidth forecasting and dynamic bandwidth allocation into a broadband communication system

• US 7,920,594 B2
• Filed: 02/19/2009
• Issued: 04/05/2011
• Est. Priority Date: 05/19/2000
• Status: Expired due to Fees

• Current Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Original Assignee: Scientific-Atlanta LLC (Cisco Systems, Inc.)
• Inventors: Carlson, William S., Moyer, Matthew James, McKinnon, Martin William III, Rufus, Freeman Jr., Hart, John Bradford
• Primary Examiner(s): NGUYEN, HANH N
• Application Number:
  US12/388,663
• Publication Number:
  US 20090213871A1
• Time in Patent Office: 775 Days
• Field of Search: 370/395.21, 370/395.41, 370/395.42, 370/468, 370/395.4, 370/486, 370/487, 455/452, 455/450, 455/453, 725/91, 725/95, 725/96, 725/97, 725/98, 725/103, 725/111, 725/114, 725/118, 725/143, 725/144, 725/148, 725/151
• US Class Current: 370/468
• CPC Class Codes: H04L 12/2801 Broadband local area networks
• CPC Class Codes: H04L 12/2856 Access arrangements, e.g. Internet access asynchronous transfer mode networks H04L12/5601; broadband local area networks H04L12/2801; optical access or distribution networks H04Q11/0067; access to open networks H04L12/5691; digital subscriber line end-user equipment and bit-level processing of data on a PSTN-based network H04M11/00; home network gateways H04L12/2834; wireless access networks H04W
• CPC Class Codes: H04L 12/2861 Point-to-multipoint connection from the data network to the subscribers
• CPC Class Codes: H04L 12/2865 Logical combinations
• CPC Class Codes: H04L 12/2876 Handling of subscriber policies group policies management H04L41/0893
• CPC Class Codes: H04L 41/0896 Bandwidth or capacity management, i.e. automatically increasing or decreasing capacities flow or congestion control using dynamic resource allocation, e.g. in-call renegotiation, H04L47/76
• CPC Class Codes: H04L 41/147 for predicting network behaviour
• CPC Class Codes: H04L 41/5003 Managing SLA; Interaction between SLA and QoS
• CPC Class Codes: H04L 41/5009 Determining service level performance parameters or violations of service level contracts, e.g. violations of agreed response time or mean time between failures [MTBF]
• CPC Class Codes: H04L 41/5019 Ensuring fulfilment of SLA
• CPC Class Codes: H04L 41/5022 by giving priorities, e.g. assigning classes of service
• CPC Class Codes: H04L 41/5029 Service quality level-based billing, e.g. dependent on measured service level customer is charged more or less
• CPC Class Codes: H04L 41/5067 Customer-centric QoS measurements
• CPC Class Codes: H04L 41/5087 wherein the managed service relates to voice services management of VoIP services H04M7/0081
• CPC Class Codes: H04L 41/509 wherein the managed service relates to media content delivery, e.g. audio, video or TV
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks
• CPC Class Codes: H04L 43/022 by sampling
• CPC Class Codes: H04L 43/045 for graphical visualisation of monitoring data
• CPC Class Codes: H04L 43/06 Generation of reports
• CPC Class Codes: H04L 43/062 related to network traffic
• CPC Class Codes: H04L 43/067 : using time frame reporting
• CPC Class Codes: H04L 43/0829 : Packet loss
• CPC Class Codes: H04L 43/0882 : Utilisation of link capacity
• CPC Class Codes: H04L 43/0888 : Throughput
• CPC Class Codes: H04L 43/106 : using time related information in packets, e.g. by adding timestamps
• CPC Class Codes: H04L 43/12 : Network monitoring probes
• CPC Class Codes: H04L 43/16 : Threshold monitoring
• CPC Class Codes: H04L 45/245 : Link aggregation, e.g. trunking
• CPC Class Codes: H04L 47/10 : Flow control; Congestion control
• CPC Class Codes: H04L 47/11 : Identifying congestion
• CPC Class Codes: H04L 47/12 : Avoiding congestion; Recovering from congestion
• CPC Class Codes: H04L 47/125 : by balancing the load, e.g. traffic engineering
• CPC Class Codes: H04L 47/127 : by using congestion prediction
• CPC Class Codes: H04L 47/15 : in relation to multipoint traffic arrangements for broadcast or multicast in data networks H04L12/18
• CPC Class Codes: H04L 47/20 : Traffic policing
• CPC Class Codes: H04L 47/24 : Traffic characterised by specific attributes, e.g. priority or QoS
• CPC Class Codes: H04L 47/263 : Rate modification at the source after receiving feedback
• CPC Class Codes: H04L 47/28 : in relation to timing considerations
• CPC Class Codes: H04L 47/29 : using a combination of thresholds
• CPC Class Codes: H04L 47/41 : by acting on aggregated flows or links
• CPC Class Codes: H04L 47/70 : Admission control; Resource allocation
• CPC Class Codes: H04L 47/762 : triggered by the network
• CPC Class Codes: H04L 47/788 : Autonomous allocation of resources
• CPC Class Codes: H04L 47/805 : QOS or priority aware
• CPC Class Codes: H04L 47/808 : User-type aware
• CPC Class Codes: H04L 47/822 : Collecting or measuring resource availability data
• CPC Class Codes: H04L 47/824 : Applicable to portable or mobile terminals
• CPC Class Codes: H04L 47/826 : Involving periods of time
• CPC Class Codes: H04L 47/828 : Allocation of resources per group of connections, e.g. per group of users
• CPC Class Codes: H04L 47/83 : based on usage prediction
• CPC Class Codes: H04N 21/2385 : Channel allocation H04N21/266 takes precedence; Bandwidth allocation H04N21/24 takes precedence ; allocation of channels according to the instantaneous demands of the users in time-division multiplex systems H04J3/1682; admission control, resource allocation in open networks H04L12/5692; arrangements for maintenance or administration in data switching networks involving bandwidth and capacity management H04L41/0896; negotiating bandwidth in wireless networks H04W28/16
• CPC Class Codes: H04N 21/2408 : Monitoring of the upstream path of the transmission network, e.g. client requests monitoring data switching networks utilization H04L43/0876; scheduling or organising the servicing of application requests H04L67/60
• CPC Class Codes: H04N 21/6118 : involving cable transmission, e.g. using a cable modem
• CPC Class Codes: H04N 21/64738 : Monitoring network characteristics, e.g. bandwidth, congestion level data switched network analysis H04L41/14; monitoring functioning in data switched networks H04L43/0817; flow control in packet networks H04L47/10
• CPC Class Codes: H04N 7/17309 : Transmission or handling of upstream communications
• CPC Class Codes: Y02D 30/50 : in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method for providing network access to a shared access communications medium for a plurality of users includes the steps of conducting predictive admission control by arbitrating user requests for access to the shared medium based on predicted aggregate demands, conducting lookahead scheduling for use in making user channel assignments by forecasting schedule transmission opportunities one or more channels of the shared medium, and balancing load by making channel assignments such that a plurality users are each assigned a respective channel of the shared medium based upon a predicted need. Congestion parameters can predicted for each channel of the shared medium and mapped to a congestion measure using a mathematical function that takes into account packet loss rate, packet delay, packet delay jitter, and available capacity.

Claims

1. A cable modem, comprising:

a media access control (MAC) layer;

communication components coupled to the MAC layer operative for communicating digital data over a shared access communication medium;

a statistics collector coupled to the MAC layer for collecting statistical information relating to traffic in the media access control (MAC) layer;

a lookahead scheduler coupled to the MAC layer operative for forecasting schedule transmission opportunities on a given channel, wherein the lookahead scheduler is configured to assign a forecasting function to a user based on whether or not a cycle has been detected via an autocorrelation function and a identifier function, and wherein the autocorrelation function identifies elements in a time series which are influential on a current observation of that same series and the identifier function identifies possible cycles of the time series by identifying local maxima output by the autocorrelation function; and

a predictor responsive to the statistical information collected by the statistics collector, for generating prediction signals representative of future bandwidth requirements.

2. The cable modem of claim 1, wherein the communication components are compatible with the Data Over Cable System Interface Specification (DOCSIS).

3. The cable modem of claim 1, wherein the components operative for communicating digital data comprises a component for communicating the prediction signals to a cable modem termination system (CMTS) for load balancing and predictive admission control.

4. The cable modem of claim 1, further comprising a statistics library for storing the statistical information from the statistics collector.

5. The cable modem of claim 1, wherein the lookahead scheduler is configured to assign a Holtz-Winters seasonal cycle exponential smoothing function when the autocorrelation function detects a cycle and assign an adaptive-response-rate single exponential smoothing function when the autocorrelation function does not detect a cycle.

6. A cable modem termination system (CMTS) configured to making channel assignments to users and to load-balance a plurality of channels on a shared access communications medium comprising:

a prediction filter for receiving prediction signals representative of future bandwidth requirements of users on the shared medium;

a prediction cache coupled to the prediction filter for storing prediction signals received by the prediction filter;

a media access control (MAC) layer coupled to the prediction cache;

a load balancer coupled to the MAC layer for making channel assignments such that a plurality users are each assigned a respective channel of the shared medium based upon the prediction signals and one or more rules for bandwidth allocation;

a lookahead scheduler coupled to the MAC layer operative for forecasting schedule transmission opportunities on a given channel, wherein the lookahead scheduler is configured to assign a forecasting function to a user based on whether or not a cycle has been detected via an autocorrelation function and a identifier function, and wherein the autocorrelation function identifies elements in a time series which are influential on a current observation of that same series and the identifier function identifies possible cycles of the time series by identifying local maxima output by the autocorrelation function; and

a rule storage element coupled to the MAC layer for storing the one or more rules for bandwidth allocation.

7. The CMTS of claim 6, wherein the one or more rules comprise modifying bandwidth available to individual ones of the plurality of users according to at least one of the following:

based on a service level agreement (SLA), based on user priority, based on traffic type priority, by changing service flow parameters, and by changing quality of service parameters.

8. The CMTS of claim 6, wherein the system is compatible with the Data Over Cable System Interface Specification (DOCSIS).

9. The CMTS of claim 6, wherein the prediction signals are provided by a communications device coupled to the shared access communication system.

10. The CMTS of claim 6, wherein the load balancer is configured to determine surplus bandwidth available on the respective channel, wherein if surplus bandwidth exists on the respective channel then allocating the surplus bandwidth to individual ones of the plurality of users by at least one of the following:

user, user class, user within a class, fee per unit bandwidth, and bandwidth credit.

11. The CMTS of claim 6, wherein the CMTS is further configured to dynamically update a user'"'"'s service level agreement (SLA) when it is determined that the user'"'"'s demand exceeds that provided for in the SLA or when it is determined that the user'"'"'s demand falls short of that provided for in the SLA, and further configured to giving the user an option to accept or reject said updated SLA.

12. A data communications system for controlling network access of a plurality of users to a shared access communications medium, the system comprising:

one or more cable modems coupled to the shared medium;

a cable modem termination system (CMTS) coupled to the shared medium, the CMTS having a media access control (MAC) layer;

a statistics collector coupled to the MAC layer for collecting statistical flow information relating to service flows on the shared medium;

a lookahead scheduler coupled to the MAC layer operative for forecasting schedule transmission opportunities on a given channel, wherein the lookahead scheduler is configured to assign a forecasting function to a user based on whether or not a cycle has been detected via an autocorrelation function and a identifier function, and wherein the autocorrelation function identifies elements in a time series which are influential on a current observation of that same series and the identifier function identifies possible cycles of the time series by identifying local maxima output by the autocorrelation function;

a statistics cache coupled to the statistics collector for storing the statistical flow information;

a prediction filter coupled to the shared medium for receiving prediction signals from the one or more cable modems, the prediction signals representative of future bandwidth requirements of users of the shared medium;

a prediction cache coupled to the prediction filter for storing prediction signal information;

a service flow manager coupled to the statistics cache and to the prediction cache for dynamically adjusting quality of service (QoS) parameters of service flows responsively to each of the statistical flow information, the prediction signal information, and rules relating to control of access to the shared medium;

a load balancer coupled to the statistics cache and to the prediction cache for dynamically making channel assignments such that one or more users are each assigned a respective channel of the shared medium responsively to each of the statistical flow information, the prediction signal information, and rules relating to control of access to the shared medium; and

a rule base coupled to the service flow manager and to the load balancer for storing the rules relating to control of access to the shared medium and providing the rules to the service flow manager and load balancer.

13. The system of claim 12, wherein the system is compatible with the Data Over Cable System Interface Specification (DOCSIS).

14. The system of claim 13, wherein the load balancer is operative for dynamically changing a channel assignment of a cable modem via a DOCSIS MAC layer dynamic channel change mechanism.

15. The system of claim 14, wherein the service flow manager is coupled to the MAC layer of the CMTS and is operative for adjusting service flows via a DOCSIS MAC layer service interface.

16. The system of claim 12, wherein the statistics collector collects statistics from the traffic data interface of the MAC layer of the CMTS.

17. The system of claim 12, wherein the prediction filter is responsive to prediction signals provided by cable modems and stores prediction signal information in the prediction cache.

18. The data communications system of claim 12, wherein the load balancer is configured to determine surplus bandwidth available on the respective channel, wherein if surplus bandwidth exists on the respective channel allocating the surplus bandwidth to individual ones of the plurality of users by at least one of the following:

user, user class, user within a class, fee per unit bandwidth, and bandwidth credit.

19. The data communications system of claim 12, wherein the CMTS is configured to dynamically update a user'"'"'s service level agreement (SLA) when it is determined that the user'"'"'s demand exceeds that provided for in the SLA or when it is determined that the user'"'"'s demands falls short of that provided for in the SLA, and further operative for giving the user an option to accept or reject said updated SLA.