Method for transmitting data in a wireless network, and wireless network therefor
Method for transmitting data from a resource-constrained transmitter to a receiver in a wireless network, comprising the following steps:—the resource-constrained transmitter ( 21 a, 21 b, 21 c ) sending a channel request message to the receiver,—in response to the request, the receiver ( 22 ) determining communication channel availability based on the result of a sensing step and broadcasting channel information,—the resource-constrained transmitter ( 21 a, 21 b, 21 c ) listening to the information and transmitting data on the corresponding channel, wherein the sensing step is performed by the receiver before or after receiving channel request from the transmitter. The invention also relates to a wireless network.
1. A method for transmitting data from a resource-constrained transmitter to a receiver in a wireless network, comprising:
sending a channel request message to the receiver, the channel request message requesting the receiver to determine an available communication channel,
listening for the channel request message by the receiver during periodic predetermined slots,
in response to the channel request message, the receiver determining communication channel availability based on sensing the wireless network during a sensing slot and then broadcasting channel information associated with at least one channel,
the transmitter listening to the channel information and then transmitting data on the at least one channel, and
the receiver going into a power saving mode when the channel request message is not received during one of the periodic predetermined slots.
2. The method according to claim 1 , wherein the resource-constrained transmitter is a low-power sensor node.
3. The method according to claim 1 , wherein sensing the wireless network is performed periodically by the receiver during predetermined sensing slots.
4. The method according to claim 3 , wherein sending the channel request message is performed before expiration of a delay after a sensing slot.
5. The method according to claim 4 , wherein the receiver goes into the power saving mode until a next sensing slot when the channel request message is not received at expiration of the delay.
6. The method according to claim 1 , wherein sensing the wireless network is performed upon receiving the channel request message from the resource-constrained transmitter.
7. The method according to claim 6 , wherein sending the channel request message is performed during a one of pre-allocated time slots known by the receiver.
8. The method according to claim 7 , wherein the receiver goes into the power saving mode after the pre-allocated time slot when the channel request message is not received, until a next pre-allocated time slot.
9. The method according to claim 1 , wherein determining the communication channel availability is performed by taking into account transmission characteristics of the resource-constrained transmitter and of other devices in the wireless network.
10. A wireless network, comprising:
a resource-constrained transmitter for transmitting data to a receiver, and for sending a channel request message to the receiver when the data is transmitted, the channel request message requesting the receiver to determine an available communication channel, and
a receiver for listening for the channel request message during periodic predetermined slots, determining channel availability by sensing the wireless network during a sensing slot and for transmitting channel information associated with at least one channel to the resource-constrained transmitter upon receipt of the channel request message,
wherein the receiver is further configured to go into a power saving mode when the channel request message is not received during one of the periodic predetermined slots.
11. A resource-constrained device for transmitting data in a wireless network, comprising:
a memory; and
a transmitter configured to:
send a channel request message to a receiver when the device has to transmit data to the receiver, the channel request message requesting the receiver to determine an available communication channel, wherein the receiver is configured to listen for the channel request message during periodic predetermined slots, determine channel availability by sensing the wireless network during a sensing slot and go into a power saving mode when the channel request message is not received during one of the periodic predetermined slots;
receive an allocated communication channel information from the receiver; and
transmit the data using the allocated communication channel.
12. A method for transmitting data by a resource-constrained device in a wireless network, comprising:
sending a channel request message to a receiver when the device has to transmit data to the receiver, the channel request message requesting the receiver to determine an available communication channel, wherein the receiver is configured to listen for the channel request message during periodic predetermined slots, determine channel availability by sensing the wireless network during a sensing slot and go into a power saving mode when the channel request message is not received during one of the periodic predetermined slots;
receiving an allocated communication channel information from the receiver; and
transmitting the data using the allocated communication channel.