Rate control techniques for efficient high speed data services

• US 6,219,343 B1
• Filed: 07/29/1997
• Issued: 04/17/2001
• Est. Priority Date: 07/29/1997
• Status: Expired due to Term

• Current Assignee: Nokia Solutions and Networks US LLC (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Honkasalo, Zhichun, Parantainen, Janne, Ma, Lin
• Primary Examiner(s): Nguyen, Chau
• Assistant Examiner(s): BOAKYE, ALEXANDER O
• Application Number:
  US08/902,236
• Time in Patent Office: 1,358 Days
• Field of Search: 370/319, 370/320, 370/335, 370/395, 370/441, 370/252, 370/465, 370/468, 370/329, 370/330, 379/59, 455/422
• US Class Current: 370/335
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04B 7/264 for data rate control
• CPC Class Codes: H04W 52/267 taking into account the information rate
• CPC Class Codes: H04W 52/343 taking into account loading or congestion level

Abstract

Methods for controlling data rate allocations to data packet users transmitting packet data over a CDMA cellular communication network are defined which comprises the steps of: evaluating traffic channels and radio capacity allocated for packet data services within the network to determine an available resource for a packet data transmission; employing a rate control algorithm to determine a data rate allocation for the packet data transmission; and limiting the transmit power of a transmitter to provide the determined data rate allocation for the packet data transmission. The methods include a rate control algorithm which determines data rate allocation using a transmission power budget technique and a rate control algorithm which determines data rate allocation using a current system load technique.

Claims

1. A method for controlling data rate allocations to data packet users transmitting packet data over a code division multiple access (CDMA) cellular communication network, comprising the steps of:

evaluating traffic channels and radio capacity allocated for packet data services within the network to determine an available resource for a packet data transmission;

employing a rate control algorithm to determine a data rate allocation for the packet data transmission; and

controlling the radio capacity occupied by the packed data user by limiting the transmit power of a transmitter required to provide the determined data rate allocation for the packet data transmission;

wherein said rate control algorithm increases system throughput by assigning the highest available data rate to a packet data user having the smallest path loss.

2. A method for controlling data rate allocations according to claim 1, wherein the rate control algorithm determines the data rate allocation using a transmission power budget technique.

3. A method for controlling data rate allocations according to claim 2, wherein the transmission power budget technique for receiving a single transmission requests at one time comprises the steps of:

determining an unused capacity of each BS within the network that is allocatable for packet data transmission;

wherein the unused capacity of each of the BSs within the network is allocatable, calculating a maximum available data rate assignable by each of the BSs to a requesting MS without causing an overflow of a cell;

comparing the maximum available date rates of each of the BSs within the network and selecting a minimum data rate which results in a smallest path loss; and

assigning the BS within the network with the minimum data rate to the requesting MS for packet data transmission.

4. A method for controlling data rate allocations according to claim 3, wherein the step of determining the unused capacity of each of the BSs within the network that is allocatable for packet data transmission further comprises the step of;

comparing the total budget transmission power for packet services (P_t) of each of the BSs within the network to a current total transmission power allocated by the BS (P_i) according to the following formula,

5. A method for controlling data rate allocations according to claim 3, wherein the step of calculating a maximum available data rate assignable by each of the BSs to the requesting MS without causing the overflow of the cell further comprises the steps of;

initializing a variable (k_i) which represents a data rate in which packet data is transmitted by each of the BSs;

calculating a transmission power level to be made available to the requesting MS by multiplying the data rate (k_i) by a current level of transmission power (C_i);

adding the transmission power to be made available (k_i×

C_i) to a current total transmission power allocated by the BS (P_i) wherein a proposed total transmission power allocation for each of the BSs is produced; and

performing a cyclic comparison of a total budget transmission power for packet services (P_t) of each of the BSs to the proposed total transmission power allocation for each BS according to the following formula,

6. A method for controlling data rate allocations according to claim 2, wherein the transmission power budget technique for receiving several transmission requests at one time comprises the steps of:

adding to a waiting list each received MS transmission request;

evaluating each transmission request in the waiting list to determine a selected MS with a smallest path loss from the waiting list;

assigning the BS with the minimum data rate to the selected MS from the waiting list for packet data transmission;

removing the selected MS request from the waiting list; and

updating a current total transmission power level to be made available for each of the BSs according to the following formula,

7. A method for controlling data rate allocations according to claim 6, wherein the step of evaluating each transmission request in the waiting list to determine the smallest path loss from the waiting list further comprises the steps of;

determining an unused capacity of each of the BSs within the network that is allocatable for packet data transmission;

wherein the unused capacity of each of the BSs is allocatable, calculating a maximum available data rate assignable by each of the BSs to the requesting MS without causing an overflow of a cell; and

comparing the maximum available date rates of each of the BSs within the network and selecting a minimum data rate which results in a smallest path loss.

8. A method for controlling data rate allocations according to claim 1, wherein the rate control algorithm determines the data rate allocation using a current system load technique.

9. A method for controlling data rate allocations according to claim 8, wherein the current system load technique for transmission requests from a MS to a BS having i=1 to n load thresholds and j=1 to m data rate regions where m=n+1, comprises the steps of:

determining a current load of a cell (L_c) allocated to packet data users for packet transmission;

comparing an ith load threshold, L_i, to the current system load, L_c, according to the following formula,

10. A cellular communication system, comprising:

at least one base station having a transmitter and an associated cell; and

at least one mobile station located within said cell, said at least one mobile station providing packet data services;

wherein said base station comprises a controller for evaluating traffic channels and radio capacity allocated for packet data services within said cell to determine an available resource for a packet data transmission;

said controller employing a rate control algorithm to determine a data rate allocation for a packet data transmission;

said controller controlling said radio capacity occupied by said mobile station by limiting said transmit power of said transmitter to that required to provide said determined data rate allocation for said packet data transmission; and

said rate control algorithm increases system throughput by assigning the highest available data rate to a mobile station having the smallest path loss.