System and method for channel scanning in wireless networks
View Patent ↗Channel scanning for wireless networks, such as Wireless Local Area Networks (WLANs), generally provides a wireless station with the information on the available WLAN resources, such as the frequency band and the maximum transmission power. The present invention provides safe and fast domain-aware channel scanning, enabling a wireless station to comply with applicable local regulations, in spite of the possibility of domain changes, with short channel-scanning time. Fast channel scanning is accomplished by active channel scanning if valid domain information is available and there is no possibility of domain change. Also, domain-independent channels, if any, are first scanned using active scan to get domain information faster.
1. A telecommunication system comprising:
a network;
a wireless station comprising:
a receiver for receiving a data block, wherein said data block comprises a domain change pre-alert field;
a controller coupled to said receiver, said controller selecting a channel scanning method based upon data in said domain change pre-alert field, said data in said domain change pre-alert field being based on geographic information of the access point; and
a transmitter coupled to said controller; and
an access point providing said data block to said wireless station.
2. The telecommunication system of claim 1 , wherein the transmitter transmits a probe frame if said domain change pre-alert field is not set.
3. The telecommunication system of claim 1 , wherein said data in said domain change pre-alert field is based on information related to proximity of the access point to a predetermined point.
4. The telecommunication system of claim 1 , wherein said data in said domain change pre-alert field is based on a maximum coverage area and geographical information of the access point.
5. A telecommunication system comprising:
a network; and
a wireless station comprising:
a receiver for receiving a data block, wherein said data block comprises a lifetime field based upon a maximum handover time;
a controller coupled to said receiver, said controller selecting a channel scanning method based upon data in said lifetime field, said channel scanning method being selected from among active and passive scanning methods; and
a transmitter coupled to said controller; and an access point providing said data block to said wireless station.
6. The telecommunication system of claim 5 , wherein said lifetime field is based upon the shortest distance from a domain boundary to an edge of a coverage area of the access point.
7. The telecommunication system of claim 5 , wherein said lifetime field is based upon a maximum speed of said wireless station.
8. The telecommunication system of claim 5 , further comprising performing a safe channel scan if an elapsed period of time after the communication between said wireless station and said access point has been lost is greater than a period of time in said lifetime field.