Voice over Internet protocol (VoIP) call admission and call regulation in a wireless network

• US 20060133346A1
• Filed: 12/17/2004
• Published: 06/22/2006
• Est. Priority Date: 12/17/2004
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Martin, Charles, Chheda, Ashvin H.
• Granted Patent: US 7,474,627 B2
• Time in Patent Office: Days
• US Class Current: 370/352
• CPC Class Codes: H04L 47/11 Identifying congestion
• 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 47/283 in response to processing delays, e.g. caused by jitter or round trip time [RTT]
• CPC Class Codes: H04L 47/70 Admission control; Resource allocation
• CPC Class Codes: H04L 47/745 Reaction in network
• CPC Class Codes: H04L 47/801 Real time traffic
• 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: H04W 28/02 Traffic management, e.g. flow control or congestion control
• CPC Class Codes: H04W 8/04 Registration at HLR or HSS [Home Subscriber Server]

Abstract

A method and apparatus for providing wireless data packet call regulation and call access for wireless Voice over Internet Protocol (VoIP) communications in a wireless network. A first and second time stamp is generated upon the reception and successful transmission of a data packet. A packet delay is determined based upon the first and second time stamps. At least one average delay metric is used to determine whether to provide new call access based on the at least one average delay metric. Another aspect of the present invention is to block a class of users based, in part, on the average sector delay for each user subscriber class. If the average sector delay is greater than that allowed for a class of users, users of that class are denied access. A delay quality of service (QoS) block metric is used to determine if an individual user should be force dropped.

Claims

1. A method for providing wireless data packet access for wireless Voice over Internet Protocol (VoIP) communications in a network element of a wireless network, the method comprising:

receiving a data packet and generating a first time stamp for the data packet if the data packet did not include the first time stamp;

transmitting the received data packet to a mobile terminal;

receiving an acknowledgement (ACK) from the mobile terminal;

generating a second time stamp upon reception of the ACK from the mobile terminal if the ACK does not include the second time stamp;

determining a packet delay based upon the first and second time stamps;

producing the packet delay to at least one filter to produce at least one average delay metric; and

determining whether to provide new call access based on the at least one average delay metric.

2. The method of claim 1 wherein determining whether to provide new call access comprises:

blocking all new mobile terminals access if the at least one average delay metric is above a first threshold;

blocking access to new mobile terminals of a second class if the at least one average delay metric is below the first threshold and above a second threshold;

blocking access to new mobile terminals of the second class and a third class if the at least one average delay metric is below the second threshold and above a third threshold; and

granting all new mobile terminals access if the at least one average delay metric is below the third threshold.

3. The method of claim 1 wherein determining whether to provide new call access comprises:

blocking all new mobile terminals access if an average sector delay metric is above a first threshold;

granting access to new mobile terminals of a third class if the average sector delay metric is below the first threshold and above a second threshold;

granting access to new mobile terminals of the third class and a second class if the average sector delay metric is below the second threshold and above a third threshold; and

granting all new mobile terminals access if the average sector delay metric is below the third threshold.

4. The method of claim 1 wherein the at least one filter includes a filter that produces an average delay period for all communications.

5. The method of claim 4 wherein the at least one filter comprises a plurality of filters, at least one of which produces an average delay for communications for the mobile stations of at least one of the first, second and third classes.

6. The method of claim 1 wherein determining the packet delay further comprises:

generating a protocol utility command to one of a call source or a call destination and timing a round trip time delay from the network element.

7. The method of claim 6 wherein the network element calculates a delay budget for determining a plurality of thresholds used for call admission wherein the delay budget is determined by subtracting at least a portion of the round trip time delay as well as fixed delay values along a communication link from a total acceptable amount of delay.

8. The method of claim 1 wherein the network element receives communications with at least one time stamp value reflecting a time the data packet was originated and wherein the network element determines a delay to a destination device to calculate a total delay.

9. The method of claim 8 wherein the total delay is produced to a filter that averages total delay values for a plurality of communications to produce an average delay value that is used for comparison to at least one threshold to determine call admission.

10. The method of claim 9 wherein the step of comparing to the at least one threshold to determine call admission further comprises:

comparing the average delay value to a delay bound metric;

blocking call admission if the comparison is unfavorable; and

allowing call admission if the comparison is favorable.

11. The method of claim 10 wherein the comparing the average delay value to the delay bound metric further comprises:

decreasing the delay bound metric by a first factor if a network packet drop rate is greater than a specified first percentage;

increasing the delay bound metric by a second factor if the network packet drop rate is less than a specified second percentage; and

wherein the specified second percentage is less than the specified first percentage.

12. The method of claim 1 wherein the step of determining whether to provide new call access to a wireless communication link is based partially upon delays experienced by a communication signal in an external landline network.

13. The method of claim 1 wherein the step of determining whether to provide new call access to a wireless communication link is based partially upon:

an average delay metric per mobile terminal determined from an average delay per sector and a number of mobile terminals per sector, and

wherein the new call access may be blocked if an increase in the average delay per sector due to the new call access is greater than a delay bound.

14. A method for providing wireless data packet access for wireless Voice over Internet Protocol (VoIP) communications in a network element of a wireless network, the method comprising:

receiving a data packet and generating a first time stamp for the data packet if the first time stamp was not received with the data packet;

transmitting the received data packet to a mobile terminal;

receiving an acknowledgement (ACK) from the mobile terminal;

generating a second time stamp upon reception of the ACK from the mobile terminal if the ACK does not include the second time stamp;

determining a packet delay from the first and second time stamps;

producing the packet delay to at least one filter to produce an average delay metric; and

based upon the average delay metric produced by the at least one filter, determining whether to drop on-going calls.

15. The method of claim 14 further including determining, for a mobile terminal having an individual average call delay, dropping the mobile terminal if the individual average call delay is greater than a delay QoS drop level wherein the delay QoS drop level is one that substantially exceeds average delay values.

16. The method of claim 14 further including dropping calls based upon at least one of a plurality of factors including call duration, call type and class of service assigned to the mobile terminals engaged in calls.

17. The method of claim 16 wherein calls are dropped in an order from a lowest class to a highest class.

28. The access point of claim 17 wherein the call admission policy produces a switched call block metric that is less than a new call block metric.

18. An access point for performing call admission and call control in a wireless network, comprising:

transceiver circuitry for receiving and for transmitting data packets that include data messages and signaling messages;

at least one buffer for storing received data packets that carry data messages that can not be transmitted immediately;

at least one buffer for storing received data packets that carry signaling messages that can not be transmitted immediately;

time stamp logic for generating time stamps and for calculating a delay between the reception of a data packet and an acknowledgement of the data packet;

at least one filter for producing a plurality of average delay metrics;

sorting logic for routing the calculated delay to the at least one filter of a plurality of filters;

delay logic for generating a call admission policy based on the plurality of average delay metrics; and

scheduling logic for prioritizing the buffered data packets based on a subscriber class of service.

19. The access point of claim 18 wherein the scheduling logic prioritizes the buffered data packets based upon whether the data packets carry data messages or signaling messages, and if appropriate, the criticality of the signaling messages.

20. The access point of claim 18 wherein the call admission policy:

blocks all new mobile terminals access if the plurality of average delay metrics is above a first threshold;

grants access to new mobile terminals of a third subscriber class if the plurality of average delay metrics is below the first threshold and above a second threshold;

grants access to new mobile terminals of the third subscriber class and a second subscriber class if the plurality of average delay metrics is below the second threshold and above a third threshold; and

grants all new mobile terminals access if the plurality of average delay metrics is below the third threshold.

21. The access point of claim 18 wherein the at least one filter comprises one of an infinite impulse response (IIR) filter or a finite impulse response (FIR) filter.

22. The access point of claim 18 wherein the at least one filter comprises a plurality of filters and wherein the sorting logic routes the calculated delay to one of the plurality of filters based on at least one of a subscriber class level, a sector number, and a mobile terminal ID.

23. The access point of claim 18 wherein the call admission policy:

blocks all new mobile terminals access if an average sector delay metric is above a first threshold;

blocks access to new mobile terminals of a second class if the average sector delay metric is below the first threshold and above a second threshold;

blocks access to new mobile terminals of the third class and a second class if the average sector delay metric is below the second threshold and above a third threshold; and

grants all new mobile terminals access if the average sector delay metric is below the third threshold.

24. The access point of claim 23 wherein the call admission policy drops a mobile terminal if an individual average call delay is more than a delay QoS drop level.

25. The access point of claim 24 wherein calls are dropped in an order from a lowest class to a highest class.

26. The access point of claim 18 wherein the delay logic generates the call admission policy based on a delay bound metric wherein:

call admission is blocked if the individual average call delay is less than the delay bound metric; and

call admission is granted if the individual average call delay is less than or equal to the delay bound metric.

27. The access point of claim 26 wherein the delay logic:

decreases the delay bound metric by a first factor if a sector packet drop rate is greater than a specified first percentage for a specified period of time;

increases the delay bound metric by a second factor if the sector packet drop rate is less than a specified second percentage for the specified period of time; and

wherein the specified second percentage is less than the specified first percentage.