Fast access and control in wireless communications
View Patent ↗A wireless local area network comprises an access point and at least one wireless device. The access point indicates in a downlink transmission whether access to the network is based on active scan or polling. The indication is changeable responsive to whether a beacon transmission time is approaching, whether a new scan is to be forced or whether network traffic is about to reach an overload condition.
1. A wireless communications method, comprising:
receiving a message transmission from an access point over a medium, the message transmission including a value of access blocking information, the value of access blocking information selected from:
a first value specifying that the access point is currently allowing active scanning and power-save polling by a wireless station,
a second value specifying that the access point is currently not allowing active scanning and power-save polling by the wireless station while still allowing contention-based access by the wireless station, and
a third value indicative of a time period by which the active scanning or power-save polling by the wireless station is deferred;
refraining, when the received message transmission includes the second value, transmission of a power save poll message and a probe request message while still continuing contention-based access;
deferring, when the received message transmission includes the third value, transmission of a power save poll message or a probe request message;
transmitting, when the received message transmission includes the first value, a power save poll message or a probe request message; and
contending the medium with a reduced inter frame spaces during an inter contention interval.
2. The method recited in claim 1 , wherein the received message transmission indicates the access blocking mode of operation in a Physical Layer (PHY) header.
3. The method recited in claim 1 , wherein the received message transmission indicates the access blocking or deferring mode of operation in a Medium Access Control (MAC) header.
4. A wireless communications apparatus, comprising:
means for receiving a message transmission from an access point over a medium, the message transmission including a value of access blocking information, the value of access blocking information selected from:
a first value specifying that the access point is currently allowing active scanning and power-save polling by a wireless station,
a second value specifying that the access point is currently not allowing active scanning and power-save polling by the wireless station while still allowing contention-based access by the wireless station, and
a third value indicative of a time period by which the active scanning or power-save polling by the wireless station is deferred;
means for refraining, when the received message transmission includes the second value, transmission of a power save poll message or a probe request message while still continuing contention-based access;
means for deferring, when the received message transmission includes the third value, transmission of a power save poll message or a probe request message,
means for transmitting, when the received message transmission includes the first value, a power save poll message or a probe request message; and
means for contending the medium with a reduced inter frame space during an inter contention interval.
5. The apparatus recited in claim 4 , wherein the received message transmission indicates the access blocking mode of operation in a Physical Layer (PHY) header.
6. The apparatus recited in claim 4 , wherein the received message transmission indicates the access blocking or deferring mode of operation in a Medium Access Control (MAC) header.
7. A wireless communications system comprising an access point and a wireless station, wherein
the access point is configured to:
determine a network operation status; and
signal, to the wireless station, conditional upon the network operation status, a value of access blocking information, the value of access blocking information selected from:
a first value specifying that the access point is currently allowing active scanning and power-save polling by the wireless station,
a second value specifying that the access point is not allowing active scanning and power-save polling by the wireless station while still allowing contention-based access by the wireless station, and
a third value indicative of a time period by which the active scanning or power-save polling by the wireless station is deferred; and
the wireless station is configured to:
receive data during a contention-free period over a medium;
ascertain, based on a received more-data field, that the contention-free period can be ended,
transmit a message indicating that the contention-free period has ended; and
contend the medium with a reduced inter frame space during an inter contention interval based on the received more-data field.
8. The wireless communication system of claim 7 , wherein the signaling the access blocking information further comprises signaling the value of access blocking information via a field in a downlink transmission frame.
9. The wireless communication system of claim 8 , wherein the downlink transmission frame is a PHY layer frame.
10. The wireless communication system of claim 7 , wherein the determining the network operation status includes determining congestion on a backhaul link from the access point to a core network.
11. The wireless communications system of claim 7 , wherein the reduced inter frame spaces comprise reduced Function Inter Frame Space (RPIFS), reduced Distributed Coordination Function Inter Frame Space (RDIFS), and reduced Arbitration Inter Frame Space (RAIFS).
12. The wireless communications method of claim 1 , wherein the inter contention interval is an inter Transmit Opportunity (inter-TXOP) contention interval.
13. The wireless communications method of claim 1 , wherein the reduced inter frame spaces comprise reduced Function Inter Frame Space (RPIFS), reduced Distributed Coordination Function Inter Frame Space (RDIFS), and reduced Arbitration Inter Frame Space (RAIFS).
14. The wireless communications method of claim 13 , wherein the RPIFS is equal to Short Inter Frame Space (SIFS).
15. The wireless communications method of claim 13 , wherein the RDIFS is equal to Short Inter Frame Space (SIFS) plus a slot time.
16. The wireless communications apparatus of claim 4 , wherein the inter contention interval is an inter Transmit Opportunity (inter-TXOP) contention interval.
17. The wireless communications apparatus of claim 4 , wherein the reduced inter frame spaces comprise reduced Function Inter Frame Space (RPIFS), reduced Distributed Coordination Function Inter Frame Space (RDIFS), and reduced Arbitration Inter Frame Space (RAIFS).
18. The wireless communications apparatus of claim 17 , wherein the RPIFS is equal to Short Inter Frame Space (SIFS).
19. The wireless communications apparatus of claim 17 , wherein the RDIFS is equal to Short Inter Frame Space (SIFS) plus a slot time.