Beamforming and distributed opportunistic scheduling in wireless networks
First Claim
Patent Images
1. A method for improving performance and/or energy utilization in a WLAN system, comprising:
- a) inducing fluctuations in signal strength transmitted from an access point to stations within a transmission range of the access point; and
b) exploiting the induced fluctuations using a distributed scheduling algorithm to make the stations channel aware and opportunistic, said distributed scheduling algorithm including that said stations are induced to wait to transmit packets until the induced fluctuations in signal strength transmitted from the access point cause said stations to have a certain link quality.
3 Assignments
0 Petitions
Accused Products
Abstract
A system and method that addresses the issue of inducing and exploiting multi-user diversity in, e.g., a WLAN system in a fully distributed and opportunistic manner. In some embodiments, the system includes: an access point having a variable beamformer configured to fluctuate signal strength as perceived by stations within a range of the access point; and a plurality of stations having modified distributed-MAC protocol such as to be channel-aware and opportunistic.
42 Citations
25 Claims
-
1. A method for improving performance and/or energy utilization in a WLAN system, comprising:
-
a) inducing fluctuations in signal strength transmitted from an access point to stations within a transmission range of the access point; and b) exploiting the induced fluctuations using a distributed scheduling algorithm to make the stations channel aware and opportunistic, said distributed scheduling algorithm including that said stations are induced to wait to transmit packets until the induced fluctuations in signal strength transmitted from the access point cause said stations to have a certain link quality.
-
-
2. A system for enhancing the performance of a WLAN system, comprising:
-
a) an access point having a variable beamformer configured to fluctuate signal strength as perceived by stations within a range of the access point; b) a plurality of stations having modified distributed-MAC protocol such as to be channel-aware and opportunistic using a distributed scheduling algorithm, said distributed scheduling algorithm including that said stations are induced to wait to transmit packets until the induced fluctuations in signal strength transmitted from the access point cause said stations to have a certain link quality and wherein said stations are configured such that their MAC behavior depends on their perceived link quality. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A method for enhancing a WLAN infrastructure system, comprising:
-
using Distributed Opportunistic Scheduling (DOS) to exploit an access point radiation-beam induced multi-user diversity, providing variations in channel conditions among users, by transmitting back-to-back packets when channel conditions are favorable to reduce inter-transmission delays and by withholding transmission when channel conditions are un-favorable to reduce collision probability using a distributed scheduling algorithm, said distributed scheduling algorithm including said stations waiting to transmit packets until induced fluctuations in signal strength transmitted from the access point cause said stations to have a high link quality and said stations varying their MAC behavior based on their perceived link quality.
-
-
25. An improved WLAN system, comprising:
-
a) an access point including; a distributed opportunistic scheduling unit configured to make scheduling decisions about which station to transmit packets to and which medium access mode to operate in; a poll control unit configured to send messages to stations and to receive responses from stations and to report to said distributed opportunistic scheduling unit based on said responses; and a beamform controller unit configured to control an antenna to form specific beam patterns; and b) at least one mobile station including; a distributed opportunistic scheduling unit configured to make scheduling decisions, which computes quality metrics with the access point and decides the mode of operation before starting a transmission process.
-
Specification