Method and apparatus for forward link rate scheduling

• US 7,054,293 B2
• Filed: 07/13/2001
• Issued: 05/30/2006
• Est. Priority Date: 02/11/1997
• Status: Expired due to Fees

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Tiedemann, Edward G. Jr., Jou, Yu-Cheun, Odenwalder, Joseph P., Lin, Yu-Chuan
• Primary Examiner(s): Nguyen, Ohau
• Assistant Examiner(s): Hyun, Soon D.
• Application Number:
  US09/905,300
• Publication Number:
  US 20020012332A1
• Time in Patent Office: 1,782 Days
• Field of Search: 370/322, 370/329, 370/330, 370/335, 370/336, 370/341, 370/342, 370/345, 370/346, 370/347, 370/348, 370/443, 370/444, 370/437
• US Class Current: 370/335
• CPC Class Codes: H04B 7/2659 for data rate control
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters
• CPC Class Codes: H04W 28/22 Negotiating communication rate
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 52/281 taking into account user or data type priority
• CPC Class Codes: H04W 52/34 TPC management, i.e. sharing limited amount of power among users or channels or data types, e.g. cell loading
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level
• CPC Class Codes: H04W 52/346 distributing total power among users or channels
• CPC Class Codes: H04W 72/1273 of downlink data flows
• CPC Class Codes: H04W 72/52 based on load
• CPC Class Codes: H04W 72/563 of the wireless resources

Abstract

In a communication system capable of variable rate transmission, scheduling of high speed data transmission improves utilization of the forward link and decreases the transmission delay in data communication. Each remote station is assigned one primary code channel for the duration of the communication with a cell. Secondary code channels of various types and transmission capabilities can be assigned by a channel scheduler for scheduled transmission of data traffic at high rates. Secondary code channels are assigned in accordance with a set of system goals, a list of parameters, and collected information on the status of the communication network. Secondary code channels can be grouped into sets of secondary code channels. Data is partitioned in data frames and transmitted over the primary and secondary code channels which have been assigned to the scheduled user.

Claims

1. A method for scheduling data transmissions on a forward link in a communication network comprising at least one cell and at least one scheduled user, said method comprising the steps of:

determining a forward link capacity available for each of said at least one cell;

assigning an assigned transmission rate to each of said at least one scheduled user for data transmission on the forward link form the at least one cell to the at least one scheduled user;

sending said assigned transmission rate to said at least one scheduled user; and

wherein said assigned transmission rate is based on said forward link capacity available for each of said at least one cell.

2. The method of claim 1 wherein said determining step, said assigning step, and said sending step are repeated every K frames, wherein K is an integer greater than or equal to one.

9. The method of claim 2 further comprising the step of:

reassigning said assigned transmission rate of zero or more of said at least one scheduled user to a temporary transmission rate, wherein said temporary transmission rate is dependent on said forward link capacity available for each of said at least one cell.

3. A method for scheduling data transmissions on a forward link in a communication network comprising at least one cell and at least one scheduled user, said method comprising the steps of:

determining a forward link capacity available for each of said at least one cell;

assigning an assigned transmission rate to each of said at least one scheduled user;

sending said assigned transmission rate to said at least one scheduled user; and

wherein said assigned transmission rate is based on said forward link capacity available for each of said at least one cell, wherein said assigning step further comprises the step of;

determining an active member set for each of said at least one scheduled user, said active member set containing at least one cell in communication with said scheduled user;

wherein said assigned transmission rare is further based on said forward link capacity available for one or more of said at least one cell in said active member set.

4. The method of claim 3 wherein said assigning step further comprises the step of:

receiving a queue size for each of said least one scheduled user, said queue size determinative of an amount of data to be transmitted to each of said at least one scheduled user; and

wherein said assigned transmission rate is further based on said queue size for each of said at least one scheduled user.

5. The method of claim 4 wherein said assigning step further comprises the step of:

creating a priority list of scheduled users, said priority list containing each of said at least one scheduled user, wherein each of said least one scheduled user is assigned a priority; and

wherein said assigned transmission rate is further based on said priority of each of said at least one scheduled user.

6. The method of claim 5 wherein said assigning step further comprises the steps of:

selecting a selected scheduled user from said priority list of scheduled users, said selected scheduled user having a highest priority among said at least one scheduled user in said priority list;

calculating a maximum supportable transmission rate for said selected scheduled user by one or more of said at least one cell in said active member set of said selected scheduled user;

selecting a minimum transmission rate from said maximum supportable transmission rates, said minimum transmission rare being defined as a maximum transmission rate; and

wherein said assigned transmission rate is at or below said maximum transmission rate.

7. The method of claim 6 wherein said assigning step further comprises the step of:

recommending a preferred transmission rate, said preferred transmission rate being based on said queue size of said selected scheduled user; and

wherein said assigned transmission rate is at or below said preferred transmission rate.

8. The method of claim 7 wherein said assigning step further comprises the steps of:

updating said forward link capacity available for one or more of said at least one cell in said active member set of said selected scheduled user to reflect a capacity allocated to said selected scheduled user; and

removing said selected scheduled user from said priority list.

10. A method for scheduling data transmissions on a forward link in a communication network comprising at least one cell and at least one scheduled user, said method comprising the steps of:

determining a forward link capacity available for each of said at least one cell;

assigning an assigned transmission rate to each of said at least one scheduled user;

sending said assigned transmission rate to said at least one scheduled user; and

wherein said assigned transmission rate is based on said forward link capacity available for each of said at least one cell, wherein said determining step, said assigning step, and said sending step are repeated every K frames, wherein K is an integer greater than or equal to one,

reassigning said assigned transmission rate of zero or more of said at least one scheduled user to to temporary transmission rate, wherein said temporary transmission rare is dependent on said forward link capacity available for each of said at least one cell, wherein said reassigning step further comprises the steps of;

creating a temporary cell list of affected cells from said at least one cell in the communication network, said affected cells having inadequate transmit power to transmit data to said at least one scheduled user.

11. The method of claim 10 wherein said reassigning step further comprises the steps of:

creating a temporary priority list of affected scheduled users, said affected scheduled users composing of said at least one scheduled user in the communication network.

12. The method of claim 11 wherein said reassigning step further comprises the steps of:

selecting an affected scheduled user from said temporary priority list of affected scheduled users, said selected affected scheduled user having a highest priority among said at least one scheduled user in said temporary priority list;

calculating a maximum temporary supportable transmission rate for said selected affected scheduled user by one or more of said at least one cell in said active member set of said selected affected scheduled user;

selecting a minimum transmission rate from said maximum temporary supportable transmission rates, said minimum transmission rate being defined as a maximum temporary transmission rate; and

wherein said temporary transmission rate is at or below said maximum temporary transmission rate and said assigned transmission rate.

13. The method of claim 12 wherein said reassigning step further comprises the steps of:

updating said forward link capacity available for one or more of said at least one cell in said active member set of said selected affected scheduled user to reflect a capacity allocated to said selected affected scheduled user; and

removing said selected affected scheduled user from said priority list.

14. A method for a communication system, comprising:

transmitting data over a primary and secondary code channels over a forward link;

assigning at least one primary code channel for a duration of a communication to transmit unscheduled transmissions of data and control messages without a delay;

assigning at least one secondary code channel for transmission of data at high rates;

assigning said secondary code channels at each scheduling period and reassigned during the scheduling period according to an available capacity of said forward link.

15. The method as recited in claim 14, further comprising:

grouping said least one secondary code channel into sets of secondary code channels, with each set defined by a unique grouping of secondary code channels.

16. The method as recited in claim 14, further comprising:

scheduling high speed data transmissions by allocating communication resources via selecting a set of secondary code channels.

17. The method as recited in claim 15, further comprising:

wherein at least one of said unique grouping of secondary code channels corresponds to an assigned transmission rate.

18. The method as recited in claim 14, further comprising:

partitioning transmitted data into data frames and each data frame partitioned into data portions for transmission on the primary and secondary code channels.

19. The method as recited in claim 18, further comprising:

encoding and spreading said data portion into data frames of said primary and secondary code channels for transmission.

20. The method as recited in claim 14, further comprising:

determining a demand far a transmit power level of the forward link,

adding or dropping one or more secondary code channels to satisfy the demand for the transmit power level at each scheduling period.

21. The method as recited in claim 14, further comprising:

receiving said primary and secondary code channels.

22. The method as recited in claim 14, further comprising:

scheduling said primary and secondary code channels transmissions based on an amount of data to be transmitted.

23. The method as recited in claim 14, further comprising:

scheduling transmission of small amounts of data on the primary code channel.

24. The method as recited in claim 14, further comprising:

scheduling transmission of larger amounts of data on the secondary code channel.

25. The method as recited in claim 14, further comprising:

scheduling high data rate transmission on the secondary code channel.

26. The method as recited in claim 14, further comprising:

scheduling said primary and secondary code channels transmissions based on at least one a transmit energy-per-bit required by a user for a requisite level of performance, an amount of data to be transmitted, a type of data to be transmitted, a type of data service being provided to the user, an amount of delay already experienced by the user, and priority of the users.

27. An apparatus for a communication system, comprising:

a transmitter for transmitting data over a primary and secondary code channels over a forward link;

a controller for assigning at least one primary code channel for a duration of a communication to transmit unscheduled transmissions of data and control messages without a delay, for assigning at least one secondary code channel for transmission of data at high rates, and for assigning said secondary code channels at each scheduling period and reassigned during the scheduling period according to an available capacity of said forward link.

28. The apparatus as recited in claim 27, wherein said controller is for grouping said least one secondary code channel into sets of secondary code channels, with each set defined by a unique grouping of secondary code channels.

29. The apparatus as recited in claim 27, wherein said controller is for scheduling high speed data transmissions by allocating communication resources via selecting a set of secondary code channels.

30. The apparatus as recited in claim 28 wherein at least one of said unique grouping of secondary code channels corresponds to an assigned transmission rate.

31. The apparatus as recited in claim 27, wherein said controller is for partitioning transmitted data into data frames and each data frame partitioned into data portions for transmission on the primary and secondary code channels.

32. The apparatus as recited in claim 31, wherein said transmitter is for encoding and spreading said data portion into data frames of said primary and secondary code channels for transmission.

33. The apparatus as recited in claim 27, wherein said controller is for determining a demand for a transmit power level of the forward link, and adding dr dropping one or more secondary code channels to satisfy the demand for the transmit power level at each scheduling period.

34. The apparatus as recited in claim 27, further comprising:

a receiver for receiving said primary and secondary code channels.

35. The apparatus as recited in claim 27, wherein said controller is for scheduling said primary and secondary code channels transmissions based on an amount of data to be transmitted.

36. The apparatus as recited in claim 27, wherein said controller is for scheduling transmission of small amounts of data on the primary code channel.

37. The apparatus as recited in claim 27, wherein said controller is for scheduling transmission of larger amounts of data on the secondary code channel.

38. The apparatus as recited in claim 27, wherein said controller is for scheduling high data rate transmission on the secondary code channel.

39. The apparatus as recited in claim 27, wherein said controller is for scheduling said primary and secondary code channels transmissions based on at least one a transmit energy-per-bit required by a user for a requisite level of performance, an amount of data to be transmitted, a type of data to be transmitted, a type of data service being provided to the user, an amount of delay already experienced by the user, and priority of the users.