Method and apparatus for power control in a wireless lan

• US 5,450,616 A
• Filed: 10/06/1993
• Issued: 09/12/1995
• Est. Priority Date: 07/13/1992
• Status: Expired due to Term

• Current Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Original Assignee: Sun Microsystems Incorporated (Oracle Corporation)
• Inventors: Rom, Raphael
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): VO, NGUYEN THANH
• Application Number:
  US08/132,486
• Time in Patent Office: 706 Days
• Field of Search: 455/67.1, 455/69, 455/88, 455/126, 455/127, 455/343, 455/226.1, 455/226.2, 455/115, 455/73, 455/54.1, 455/49.1, 455/63
• US Class Current: 455/69
• CPC Class Codes: H04W 52/50 at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 52/60 using different transmission rates for TPC commands

Abstract

A method and apparatus for implementing a protocol for controlling transmitter power in a wireless LAN. The LAN is assumed to include a number of nodes, each node including a transmitter and a receiver for communicating information between computers located at the node. To initiate the protocol, the transmitter of a data sending node first transmits a signal including a transmitter power signal to each of the receivers of the data receiving noes. The information contained in the transmitter power signal may be transmitted in one of the fields of the data packet of the signal. The receivers of the data receiving nodes individually transmit power control feedback signals back to the transmitter of the data sending node. Information in each of the power control feedback signals may occupy a field in the data packet transmitted from the receiver to the transmitter of the data sending node. Preferably, the transmitter power signal indicates the radiated power level of the transmitter and each of the power control feedback signals comprises an instruction instructing the transmitter to adjust its radiated power. Upon receipt of these feedback signals, the transmitter preferably adjusts its radiated power accordingly, balancing the feedback received.

Claims

1. In a wireless Local Area Network (LAN) comprising n heterogeneous nodes sending frequent unscheduled short data packets to each other, where n is an integer greater than or equal to three, and not known to the individual nodes, a method for controlling transmission power employed by data packet sending nodes for transmitting data packets, said method comprising the steps of:

a) transmitting a first and a second unscheduled short data packet signal from a first data packet sending node to a first and a second data packet receiving nodes respectively, each of said first and second unscheduled shod data packet signals comprising a transmission power value indicating the transmission power currently employed by said first data packet sending node for transmitting data packets, said first data packet sending node being equipped to adjust the transmission power it employs for transmitting data packets;

b) receiving said first and second unscheduled short data packet signals at said first and second data packet receiving nodes respectively;

c) measuring said first and second unscheduled short data packet signals'"'"' signal quality as received at said first and second data packet receiving nodes, and calculating a first and a second power setting suggestions by said first and second data packet receiving nodes based on their individually received transmission power values and measured signal qualities, said first and second data packet receiving nodes being equipped to measure quality of signals they received and calculate power setting suggestions;

d) transmitting a first and a second unscheduled power control feedback signals comprising said calculated first and second power setting suggestions from said first and second data packet receiving nodes to said first data packet sending node;

e) receiving said first and second unscheduled power control feedback signals at said first data packet sending node; and

f) adjusting the transmission power said first data packet sending node employs for transmitting data packets, based on said received first and second power setting suggestions, said first data packet sending node being equipped to determine adjustment to the transmission power it employs for transmitting data packets based on a number of power setting suggestions received.

2. The method as said forth in claim 1, wherein,

said step a) further comprises transmitting a third unscheduled short data packet signal from said first data packet sending node to a third data packet receiving node, said third unscheduled short data packet signal also comprising said transmission power value;

said step b) further comprises receiving said third unscheduled short data packet signal at said third data packet receiving node;

said step d) further comprises transmitting a third unscheduled power control feedback signal from said third data packet receiving node to said first data packet sending node, said third unscheduled power control feedback signal comprising a power setting code indicating said third data packet receiving node being not equipped to measure quality of signals received at said third data packet receiving node nor calculate power setting suggestions;

said step e) further comprises receiving said third unscheduled power control feedback signal at said first data packet sending node; and

said transmission power adjustment by said first data packet sending node in said step f) is further based on said received power setting code.

3. The method as said forth in claim 2, wherein, said method further comprises the steps of:

g) transmitting a fourth and a fifth unscheduled short data packet signal from a second data packet sending node to said first and second data packet receiving nodes respectively, each of said fourth and fifth unscheduled short data packet signals comprising a transmission power code indicating said second data packet sending node being not equipped to adjust the transmission power it employs for transmitting data packets; and

h) receiving said fourth and fifth unscheduled short data packet signals at said first and second data packet receiving nodes respectively.

4. The method as said forth in claim 3, wherein, said method further comprises the steps:

said step g) further comprises transmitting a sixth unscheduled short data packet signal from said second data packet sending node to said third data packet receiving node, said sixth unscheduled short data packet signal also comprising said transmission power code;

said step h) further comprises receiving said sixth unscheduled short data packet signal at said third data packet receiving node.

5. In a wireless Local Area Network (LAN) comprising n heterogeneous nodes sending unscheduled short data packet to each other, where n is an integer greater than or equal to three, and not known to the individual nodes, an apparatus for controlling transmission power employed by data packet sending nodes for transmitting data packets, said apparatus comprising:

a) first transmission means embodied in a first data packet sending node for transmitting a first and a second unscheduled short data packet signal from said first data packet sending node to a first and a second data packet receiving nodes respectively, each of said first and second unscheduled short data packet signals comprising a transmission power value indicating the transmission power currently employed by said first transmission means of said first data packet sending node for transmitting data packets, said first data packet sending node being equipped to adjust the transmission power of said first transmission means;

b) first and second receiving means embodied in said first and second data packet receiving nodes respectively for receiving said first and second unscheduled short data packet signals at said first and second data packet receiving nodes;

c) first and second measure/calculate means embodied in said first and second data packet receiving nodes and correspondingly coupled to said first and second receiving means for measuring said first and second unscheduled short data packet signals'"'"' signal qualities as received at said first and second data packet receiving nodes, and calculating a first and a second power setting suggestions based on their individually received transmission power values and measured signal qualities;

d) second and third transmission means embodied in said first and second data packet receiving nodes and correspondingly coupled to said first and second measure/calculate means for transmitting a first and a second unscheduled power control feedback signals comprising said calculated first and second power setting suggestions from said first and second data packet receiving nodes to said first data packet sending node;

e) third receiving means embodied in said first data packet sending node for receiving said first and second unscheduled power control feedback signals at said first data packet sending node; and

f) adjustment means embodied in said first data packet sending node and coupled to said first transmission means and said third receiving means for adjusting the transmission power said first transmission means employs for transmitting data packets, based on said received first and second power setting suggestions.

6. The apparatus as said forth in claim 5, wherein,

said first transmission means further transmits a third unscheduled short data packet signal from said first data packet sending node to a third data packet receiving node, said third unscheduled short data packet signal also comprising said transmission power value;

said apparatus further comprises g) fourth receiving means embodied in said third data packet receiving node for receiving said third unscheduled short data pocket signal at said third data packet receiving node;

said apparatus further comprises h) fourth transmission means embodied in said third data packet receiving node and coupled to said fourth receiving means for transmitting a third unscheduled power control feedback signal from said third data packet receiving node to said first data packet sending node, said third unscheduled power control feedback signal comprising a power setting code indicating said third data packet receiving node being not equipped to measure quality of signals received at said third data packet receiving node nor calculate power setting suggestions;

said third receiving means further receives said third unscheduled power control feedback signal at said first data packet sending node; and

said adjustment means further adjusts said transmission power of said first transmission means based on said received power setting code.

7. The apparatus as said forth in claim 6, wherein,

said apparatus further comprises i) fifth transmission means embodied in a second data packet sending node for transmitting a fourth and a fifth unscheduled short data packet signal from said second data packet sending node to said first and second data packet receiving nodes respectively, each of said fourth and fifth unscheduled short data packet signals comprising a transmission power code indicating said second data packet sending node being not equipped to adjust the transmission power of its transmitter;

said first and second receiving means further receive said fourth and fifth unscheduled short data packet signals at said first and second data packet receiving nodes.

8. The apparatus as said forth in claim 7, wherein,

said fifth transmission means further transmits a sixth unscheduled short data packet signal from said second data packet sending node to said third data packet receiving node, said sixth unscheduled short data packet signal also comprising said transmission power code;

said fourth receiving means further receiving said sixth unscheduled short data packet signal at said third data packet receiving node.

9. In a wireless Local Area Network (LAN) comprising n heterogeneous nodes sending frequent unscheduled short data packet to each other, where n is an integer greater than or equal to three, and not known to the individual nodes, an apparatus for controlling transmission power employed by data packet sending nodes for transmitting data packets, said apparatus comprising:

a) a first transmitter embodied in a first data packet sending node for transmitting a first and a second unscheduled short data packet signal from said first data packet sending node to a first and a second data packet receiving nodes respectively, each of said first and second unscheduled short data packet signals comprising a transmission power value indicating the transmission power currently employed by said first transmitter of said first data packet sending node for transmitting data packets, said first data packet sending node being equipped to adjust the transmission power of said first transmitter;

b) a first and a second receiver embodied in said first and second data packet receiving nodes respectively for receiving said first and second unscheduled short data packet signals at said first and second data packet receiving nodes;

c) a first and a second processor embodied in said first and second data packet receiving nodes and correspondingly coupled to said first and second receivers for measuring said first and second unscheduled short data packet signals'"'"' signal qualities as received at said first and second data packet receiving nodes, and calculating a first and a second power setting suggestions based on their individually received transmission power values and measured signal qualities;

d) a second and a third transmitter embodied in said first and second data packet receiving nodes and correspondingly coupled to said first and second processors for transmitting a first and a second unscheduled power control feedback signals comprising said calculated first and second power setting suggestions from said first and second data packet receiving nodes to said first data packet sending node;

e) a third receiver embodied in said first data packet sending node for receiving said first and second unscheduled power control feedback signals at said first data packet sending node; and

f) a third processor embodied in said first data packet sending node and coupled to said first transmitter and third receiver for adjusting the transmission power said first transmitter employs for transmitting data packets, based on said received first and second power setting suggestions.

10. The apparatus as said forth in claim 9, wherein,

said first transmitter further transmits a third unscheduled short data packet signal from said first data packet sending node to a third data packet receiving node, said third unscheduled short data packet signal also comprising said transmission power value;

said apparatus further comprises g) a fourth receiver embodied in said third data packet receiving node for receiving said third unscheduled short data packet signal at said third data packet receiving node;

said apparatus further comprises h) a fourth transmitter embodied in said third data packet receiving node and coupled to said fourth receiver for transmitting a third unscheduled power control feedback signal from said third data packet receiving node to said first data packet sending node, said third unscheduled power control feedback signal comprising a power setting code indicating said third data packet receiving node being not equipped to measure packet signals received at said third data packet receiving node nor calculate power setting suggestions;

said third receiver further receives said third unscheduled power control feedback signal at said first data packet sending node; and

said third processor further adjusts said transmission power of said first transmitter based on said received power setting code.

11. The apparatus as said forth in claim 10, wherein,

said apparatus further comprises i) a fifth transmitter embodied in a second data packet sending node for transmitting a fourth and a fifth unscheduled short data packet signal from said second data packet sending node to said first and second data packet receiving nodes respectively, each of said fourth and fifth unscheduled short data packet signals comprising a transmission power code indicating said second data packet sending node being not equipped to adjust the transmission power of its transmitter;

said first and second receivers further receive said fourth and fifth unscheduled short data packet signals at said first and second data packet receiving nodes.

12. The apparatus as said forth in claim 11, wherein,

said fifth transmitter further transmits a sixth unscheduled short data packet signal from said second data packet sending node to said third data packet receiving node, said sixth unscheduled short data packet signal also comprising said transmission power code;

said fourth receiver further receiving said sixth unscheduled short data packet signal at said third data packet receiving node.