Channel-occupancy efficient, low power wireless networking
View Patent ↗An apparatus and method are provided for efficiently sharing a single wireless channel and for providing improved power saving. Automatic beacon “sliding” establishes a round-robin contention-free channel schedule among multiple IBSSs. Entering an idle state immediately following communication after a beacon saves power. Further power savings occur when presumptions of pending traffic may be made.
1. A method of saving power in a station, the station forming part of an ad-hoc wireless network including a plurality of stations, the method comprising:
waking to receive a beacon;
determining whether the station has traffic for at least one of the plurality of stations;
if the station has traffic for at least one station, then transmitting an ATIM designating the at least one station;
determining whether an ATIM sent by another station in the ad-hoc wireless network is one of a broadcast ATIM and a multicast ATIM designating the station;
if the ATIM is a broadcast/multicast ATIM designating the station, then receiving a broadcast/multicast packet associated with the ATIM;
determining whether a MORE DATA bit of the broadcast/multicast packet is set to a first predetermined value, thereby indicating that an other packet for the station is pending;
if the MORE DATA bit of the broadcast/multicast packet is set to the first predetermined value, then receiving the other packet;
if the MORE DATA bit of the broadcast/multicast packet is not set to the first predetermined value, then determining whether the ATIM is a unicast ATIM designating the station;
if the ATIM is a unicast ATIM designating the station, then receiving a unicast packet associated with the ATIM;
determining whether a MORE DATA bit of the unicast packet is set to the first predetermined value;
if the MORE DATA bit of the unicast packet is set to the first predetermined value, then setting a NULL timer and receiving the other packet;
if the MORE DATA bit of the unicast packet is not set to the first predetermined value, then determining whether the station has pending traffic in a first occurrence for at least one other station;
if the station has pending traffic for at least one other station, then setting the NULL timer and determining whether the station has pending traffic in a second occurrence for at least one other station;
if the station has pending traffic in the second occurrence for at least one other station, then transmitting a packet with its MORE DATA bit set to the first predetermined value and setting the NULL timer;
if the station does not have pending traffic in the second occurrence for at least one station, then determining whether the NULL timer has timed out;
if the NULL timer has not timed out, then returning to determining whether another ATIM is a unicast ATIM;
if the NULL timer has timed out, then determining whether the station has sent any data;
if the station has sent data, then sending a NULL packet with its MORE DATA bit set to a second predetermined value;
if the station has not sent data, or if the NULL packet was sent, or if the station has no pending traffic for at least one other station in the first occurrence, then the station enters an idle state before a next beacon.
2. A method of saving power in a station, the station forming part of an ad-hoc wireless network including a plurality of stations, the method comprising:
waking to receive a coordination transmission;
determining whether the station has traffic for at least one of the plurality of stations;
if the station has traffic for at least one station, then transmitting an ATIM designating the at least one station;
determining whether an ATIM sent by another station in the ad-hoc wireless network is one of a broadcast ATIM and a multicast ATIM designating the station;
if the ATIM is a broadcast/multicast ATIM designating the station, then receiving a broadcast/multicast packet associated with the ATIM;
determining whether a MORE DATA bit of the broadcast/multicast packet is set to a first predetermined value, thereby indicating that an other packet for the station is pending;
if the MORE DATA bit of the broadcast/multicast packet is set to the first predetermined value, then receiving the other packet;
if the MORE DATA bit of the broadcast/multicast packet is not set to the first predetermined value, then determining whether the ATIM is a unicast ATIM designating the station;
if the ATIM is a unicast ATIM designating the station, then receiving a unicast packet associated with the ATIM;
determining whether a MORE DATA bit of the unicast packet is set to the first predetermined value;
if the MORE DATA bit of the unicast packet is set to the first predetermined value, then setting a NULL timer and receiving the other packet;
if the MORE DATA bit of the unicast packet is not set to the first predetermined value, then determining whether the station has pending traffic in a first occurrence for at least one other station;
if the station has pending traffic for at least one other station, then setting the NULL timer and determining whether the station has pending traffic in a second occurrence for at least one other station;
if the station has pending traffic in the second occurrence for at least one other station, then transmitting a packet with its MORE DATA bit set to the first predetermined value and setting the NULL timer;
if the station does not have pending traffic in the second occurrence for at least one station, then determining whether the NULL timer has timed out;
if the NULL timer has not timed out, then returning to determining whether another ATIM is a unicast ATIM;
if the NULL timer has timed out, then determining whether the station has sent any data;
if the station has sent data, then sending a NULL packet with its MORE DATA bit set to a second predetermined value;
if the station has not sent data, or if the NULL packet was sent, or if the station has no pending traffic for at least one other station in the first occurrence, then the station enters an idle state before a next coordination transmission.