Method and apparatus for improving scheduling in packet data networks
View Patent ↗A method of scheduling packet data delivery by a communication network node uses knowledge of the incoming delays and corresponding delay budgets associated with the packet data to be scheduled. For example, a wireless communication network base station may serve a plurality of users via a time-multiplexed packet data channel, and may schedule the delivery of packet data targeted to individual ones of those users based on determining the allowable scheduling delays for the incoming packet data it receives for those users. The allowable scheduling delays for packet data received on a given data connection may be determined based on the incoming delays associated with that packet data and the corresponding end-to-end delay budget defined for that packet data. The incoming delays may be calculated from packet time information, e.g., timestamps, and/or may be estimated based on call type, network type, network distances/locations, network conditions, etc.
1. A method of scheduling delivery of delay-sensitive packet data from a wireless access point in a radio access network to wireless communication terminals supported by the wireless access point, the method comprising:
receiving packet data at the wireless access point for a number of data connections supported by the wireless access point, wherein the packet data received for each data connection targets a corresponding one or ones of the wireless communication terminals supported by the wireless access point;
determining a network transit time for the packet data received for each data connection, wherein the network transit time comprises a cumulative network transit delay experienced by the packet data in transiting from a corresponding originating network to the wireless access point;
determining a remaining time for delivery for the packet data received for each data connection, wherein the remaining time for delivery comprises the difference between an end-to-end delay budget defined for the packet data and the corresponding network transit time determined for the packet data; and
scheduling air interface transmissions of the packet data for each data connection as a function of the remaining times for delivery and radio conditions associated with the targeted ones of the wireless communication terminals.
2. The method of claim 1 , wherein said step of determining the network transit times comprises, for each data connection, pinging the corresponding originating network to determine the network transit time.
3. The method of claim 2 , wherein, for each data connection, said pinging comprises dynamically pinging the originating network and determining the network transit time as the average result of said dynamically pinging.
4. The method of claim 1 , wherein said step of determining the network transit times comprises, for each data connection, evaluating packet headers to determine overall elapsed time associated with transit of the packet data from the originating network to the wireless access point.
5. The method of claim 1 , wherein said step of determining the network transit times comprises, for the packet data received for a given data connection, storing assumed network transit times and selecting one or more of the stored network transit times as the determined network transit time for the given data connection, based on identifying information regarding one or more of: a calling party identity, calling or intermediate network identities, calling or intermediate network locations or separation distances, and calling or intermediate network types or complexities.
6. The method of claim 1 , wherein said step of determining network transit times comprises, for the packet data received for a given data connection, computing the network transit time as the sum of an assumed transit delay representing a portion of the network transit delay experienced by the packet data before its arrival at the wireless access point, and a calculated elapsed time representing the remaining portion of the network transit delay.
7. The method of claim 1 , wherein determining the end-to-end delay budget for the packet data received for a given data connection comprises selecting a predefined end-to-end delay budget value based on the type of packet data being carried on the given data connection.
8. The method of claim 1 , wherein said step of scheduling comprises preferentially scheduling transmission of packet data having smaller remaining times for delivery, in combination with preferentially scheduling transmission of packet data targeted to wireless communication terminals having better radio conditions.
9. The method of claim 1 , wherein said step of scheduling comprises preferentially scheduling transmissions of packet data targeted to those wireless communication terminals having better radio conditions, while also limiting transmission scheduling delays within the wireless access point to avoid violating any of the end-to-end budget delays.
10. A wireless access point configured to schedule delivery of delay-sensitive packet data from the wireless access point to wireless communication terminals supported by the wireless access point, said wireless access point comprising one or more processing circuits configured to:
receive packet data at the wireless access point for a number of data connections supported by the wireless access point, wherein the packet data received for each data connection targets a corresponding one or ones of the wireless communication terminals supported by the wireless access point;
determine a network transit time for the packet data received for each data connection, wherein the network transit time comprises a cumulative network transit delay experienced by the packet data in transiting from a corresponding originating network to the wireless access point;
determine a remaining time for delivery for the packet data received for each data connection, wherein the remaining time for delivery comprises the difference between an end-to-end delay budget defined for the packet data and the corresponding network transit time determined for the packet data; and
schedule air interface transmissions of the packet data for each data connection as a function of the remaining times for delivery and radio conditions associated with the targeted ones of the wireless communication terminals.
11. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to determine the network transit time for the packet data received for each data connection by pinging the corresponding originating network to determine the network transit time.
12. The wireless access point of claim 11 , wherein the one or more processing circuits are configured to dynamically ping the originating network and determine the network transit time as the average result of said dynamically pinging.
13. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to determine the network transit time for the packet data received for each data connection by evaluating packet headers to determine overall elapsed time associated with transit of the packet data for that data connection from the originating network to the wireless access point.
14. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to determine the network transit time for the packet data received for each data connection based on the wireless access point storing assumed network transit times and the one or more processing circuits selecting a stored network transit time as the determined network transit time, said one or more processing circuits being configured to perform said selecting based on identifying information regarding one or more of: a calling party identity, calling or intermediate network identities, calling or intermediate network locations or separation distances, and calling or intermediate network types or complexities.
15. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to determine the network transit time for the packet data received for each data connection based on computing the network transit time as the sum of an assumed transit delay representing a portion of the network transit delay experienced by the packet data before its arrival at the wireless access point, and a calculated elapsed time representing the remaining portion of the network transit delay.
16. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to determine the end-to-end delay budget for the packet data received for a given data connection based on selecting a predefined end-to-end delay budget value according to the type of packet data being carried on the given data connection.
17. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to schedule the air interface transmissions based on preferentially scheduling transmission of packet data having smaller remaining times for delivery, in combination with preferentially scheduling transmission of packet data targeted to wireless communication terminals having better radio conditions.
18. The wireless access point of claim 10 , wherein the one or more processing circuits are configured to schedule the air interface transmissions based on preferentially scheduling transmissions of packet data targeted to those wireless communication terminals having better radio conditions, while also limiting transmission scheduling delays within the wireless access point to avoid violating any of the end-to-end budget delays.