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

• US 7,499,453 B2
• Filed: 04/09/2003
• Issued: 03/03/2009
• Est. Priority Date: 05/19/2000
• Status: Expired due to Fees

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (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:
  US10/410,878
• Publication Number:
  US 20060120282A1
• Time in Patent Office: 2,155 Days
• Field of Search: 370/468, 370/395.4, 370/328, 370/329, 370/341, 370/395.41, 370/431, 370/432, 370/464, 370/465, 370/230, 370/235, 455/450, 455/453, 455/446, 455/455, 455/452.1
• US Class Current: 370/395.2
• 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 47/823 : Prediction of resource usage
• 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 method for providing network access to a shared access communications medium for a plurality of users, the method comprising the steps of:

conducting lookahead scheduling for use in making user channel assignments by forecasting schedule transmission opportunities on one or more channels of the shared medium;

conducting predictive admission control by arbitrating user requests for access to the shared medium based on predicted aggregate demands, wherein the step of conducting predictive admission control based on predicted aggregate demands comprises the steps of;

receiving a request for a service flow from a communication device;

comparing the demands of the request to the anticipated resources of the channel;

based on the comparing step, determining whether the request is to be granted or whether the request is to be modified; and

based on the step of determining whether to grant or modify the request, modifying the service flow of one or more communication devices to allow connectivity; and

balancing load by making channel assignments such that a plurality of users are each assigned a respective channel of the shared medium based upon a predicted need.

2. The method of claim 1, wherein the predicted need comprises a request for a predetermined increment of bandwidth (bandwidth unit).

3. The method of claim 2, wherein the predicted need is determined by reference to stored traffic information previously collected by a communications device coupled to the shared medium.

4. The method of claim 3, wherein the collected and stored traffic information relates to type of traffic, selected from the group comprising:

voice, streaming video, streaming audio, and http.

5. The method of claim 3, wherein the communications device is a cable modem (CM).

6. The method of claim 3, wherein the traffic information is selected from the group comprising:

session statistics, throughput statistics, and quality of service (QoS) statistics.

7. The method of claim 3, wherein the predicted need is calculated using real-time traffic statistics, comparable measurements, and long term measurements stored in a look-up table.

8. The method of claim 1, wherein the step of balancing load is carried out at a cable modem termination system (CMTS).

9. The method of claim 1, wherein the step of balancing load comprises:

predicting congestion parameters for each channel of the shared medium for a first predetermined time period;

predicting a bandwidth requirement of each user during the first predetermined time period, by sampling the data associated with each user over a second predetermined time periods, wherein individual bandwidth requirements are expressed as minimum, average, and maximum bit rates;

mapping the congestion parameters for each channel to a respective congestion measure for each channel of the shared medium in accordance with packet loss rate, packet delay, packet delay jitter, and available capacity associated with each channel; and

using the congestion measure, changing channel assignments of the plurality of users to balance a predicted available capacity of each channel of the shared medium over the first predetermined time period given the available capacity for each channel over the second predetermined time period, and the bandwidth requirement of each user;

wherein the channel assignment of at least one user is changed from a first channel to a second channel having a lighter load than the first channel.

10. The method of claim 9, wherein a user is assigned the most lightly loaded channel of the shared medium, given the predicted available capacity for each channel.

11. A method for providing network access to a shared access communications medium for a plurality of users, the method comprising the steps of:

conducting lookahead scheduling for use in making user channel assignments by forecasting schedule transmission opportunities on one or more channels of the shared medium;

conducting predictive admission control by arbitrating user requests for access to the shared medium based on predicted aggregate demands, wherein the step of conducting predictive admission control based on predicted aggregate demands comprises the steps of;

obtaining forecasts from a prediction cache for devices on a predetermined channel that are valid for a time interval;

determining the sum of the forecasted usage of devices connected to the network;

if the sum of the forecasted usage is less than a predetermined capacity of the channel, as adjusted to compensate for a reserve in anticipation of unexpected requests, populating a quality of service flow table populated with the values of the forecasted usage by the devices; and

if the sum of the forecasted usage is not less than the capacity of the channel, determining whether a service flow should be admitted; and

balancing load by making channel assignments such that a plurality of users are each assigned a respective channel of the shared medium based upon a predicted need.

12. The method of claim 11, wherein determining whether the service flow should be admitted is selected from the group comprising, (a) if no capacity exists for new service flows, denying the request;

(b) prioritizing all forecasts into a prioritized list and granting a new request based on the prioritized list; and

(c) granting requests that are a fixed percentage of the forecasts to all communication devices.

13. A system for controlling network access to a shared communications medium between a plurality of users, comprising:

a load balancer operative for allocating the plurality of users between channels of the shared communications medium based upon a predicted need;

a predictive admission control component operative for arbitrating user requests for access to the shared communications medium in response to predicted aggregate demands, wherein the predictive admission control component responsive to predicted aggregate demands comprises;

an input responsive to a request for a service flow from a communication device;

a comparator for comparing the demands of the request to the anticipated resources of the channel;

a component for determining, based on the comparator, whether the request is to be granted or whether the request is to be modified; and

a component operative for granting or modifying the request; and

a lookahead scheduler operative for forecasting schedule transmission opportunities on a given channel.

14. The system of claim 13, wherein the predicted need comprises a request for a predetermined increment of bandwidth (bandwidth unit).

15. The system of claim 13, wherein the load balancer is an element of a cable modem termination system (CMTS).

16. The system of claim 13, wherein the predicted need is determined by reference to traffic information collected by a communications device coupled to the communications medium.

17. The system of claim 16, wherein the traffic information relates to type of traffic, selected from the group comprising:

voice, streaming video, streaming audio, and http.

18. The system of claim 16, wherein the communications device is a cable modem (CM).

19. The system of claim 16, wherein the traffic information is selected from the group comprising:

session statistics, throughput statistics, and quality of service (QoS) statistics.

20. The system of claim 18, wherein the predicted need is computed using real-time traffic statistics, comparable measurements, and long term measurements stored in a look-up table.

21. The system of claim 13, wherein load the balancer is operative for changing the channel of communications of a selected user to a channel having a lighter load, and is further operative for:

predicting congestion parameters for each channel in the communication channel for a first predetermined time period;

predicting a bandwidth requirement of each user during the first predetermined time period, by sampling the data associated with each user over a second predetermined time periods, wherein bandwidth requirements are expressed as minimum, average, and maximum bit rates;

mapping the congestion parameters to a single measure in accordance with packet loss rate, packet delay, packet delay jitter, and available capacity for each channel of communications; and

using the single measure, moving users to different channels to balance a predicted available capacity of each channel over the first predetermined time period given the available capacity for each channel over the second predetermined time period, and the bandwidth requirement of each user.

22. The system of claim 21, wherein the system is operative for adding a user to the most lightly loaded channel, given the predicted available capacity for each channel.

23. A system for controlling network access to a shared communications medium between a plurality of users, comprising:

a load balancer operative for allocating the plurality of users between channels of the shared communications medium based upon a predicted need;

a predictive admission control component operative for arbitrating user requests for access to the shared communications medium in response to predicted aggregate demands, wherein the predictive admission control component comprises;

a component responsive to forecasts from a prediction cache for devices on a predetermined channel that are valid for a time interval;

a component for determining the sum of the forecasted usage of devices connected to the network; and

a component responsive to the sum of the forecasted usage being less than the capacity of the channel, as adjusted to compensate for a reserve in anticipation of unexpected requests, for populating a quality of service flow table populated with the values of the forecasted usage by the devices, and further responsive to the sum of the forecasted usage being not less than the capacity of the channel, for determining whether a service flow from user requests should be admitted; and

a lookahead scheduler operative for forecasting schedule transmission opportunities on a given channel.

24. The system of claim 23, wherein determining whether the service flow from user requests should be admitted is selected from the group comprising, (a) if no capacity exists for new service flows, denying the request;

(b) prioritizing all forecasts into a prioritized list and granting a new request based on a first-come-first-service basis of the prioritized list; and

(c) granting requests that are a fixed percentage of the forecasts to all communication devices.