Method and arrangement for reducing the average time needed for a communication unit to connect to a communication network
View Patent ↗A method and an arrangement are provided for reducing the time needed for a communication unit ( 18 ) to connect to a communication network ( 11 - 16; 14 - 16 ), wherein the communication unit has to listen for data transmissions on a plurality of communication channels, and to identify one of the communication channels, on which an ongoing transmission is detected, before being able to begin transmitting. The method comprises the steps of monitoring the time lapsed since last transmission on the channel was ended, and transmitting data on the channel in order to enable the communication unit ( 18 ) to detect an ongoing transmission provided that a condition of low data traffic is detected corresponding to that no further data transmission occurs on the channel during a given period of time since the last transmission on the channel was ended.
1. A method for reducing an average time needed for a communication unit to connect to a communication network, wherein said communication unit has to listen for data transmissions on a plurality of communication channels and to identify one of said plurality of communication channels, on which an ongoing data transmission is detected, before being able to begin transmitting, the method comprising:
monitoring a time lapsed since last data transmission on said one of said plurality of communication channels was ended, and
provided that a condition of low data traffic is detected corresponding to that no further data transmission on said one of said plurality of communication channels occurs during a given period of time since said last data transmission on said channel was ended, transmitting data on said channel in order to enable said communication unit to detect said ongoing data transmission,
wherein beacon frames are sent on said one of said plurality of communication channels at regular time intervals, and said given period of time is shorter than said regular time intervals.
2. The method according to claim 1 , wherein said communication network is a wireless local area network.
3. The method according to claim 2 , wherein said plurality of communication channels are within a frequency band, which is used for transmissions by a primary user, and wherein said data may be transmitted in one of said plurality of communication channels only after having checked that the frequency band of said one of said plurality of communication channels is not used for transmissions by said primary user.
4. The method according to claim 1 , wherein the beacon frames are sent on said one of said plurality of communication channels approximately every 100 ms.
5. The method according to claim 1 , wherein said given period of time is less than approximately 100 ms, preferably less than 50 ms, and most preferably less than 25 ms.
6. The method according to claim 1 , wherein said data transmitted in order to enable said communication unit to detect said ongoing data transmission is comprised of a null data frame.
7. The method according to claim 1 , wherein said data transmitted in order to enable said communication unit to detect said ongoing data transmission is sent to a broadcast address.
8. The method according to claim 1 , wherein said data transmitted in order to enable said communication unit to detect said ongoing data transmission is sent from an access point in said communications network.
9. The method according to claim 1 , wherein said data transmitted in order to enable said communication unit to detect said ongoing data transmission is sent from a mobile station connected in said communications network.
10. A system by which an average time needed to connect to a communication network is reduced, comprising:
a communication unit to:
listen for data transmissions on a plurality of communication channels, and
identify one of the plurality of communication channels on which an ongoing data transmission is detected; and
an access point to:
monitor a time lapsed since last data transmission corresponding to said ongoing data transmission on said one of said plurality of communication channels was ended,
transmit data on said channel in order to enable said communication unit to detect said ongoing data transmission, provided that a condition of low data traffic is detected corresponding to that no further data transmission on said one of the plurality of communication channels occurs during a given period of time since the last data transmission corresponding to said ongoing data transmission on the channel ended, and
send beacon frames on the one or said plurality of communication channels at regular time intervals,
wherein the given period of time is shorter than said regular time intervals.
11. The system according to claim 10 , wherein said communication network is a wireless local area network.
12. The system according to claim 10 , wherein said data transmitted in order to enable said communication unit to detect said ongoing data transmission is comprised of a null data frame.