Tracking of and communication with mobile terminals using a battery-powered wireless network infrastructure

1. A method of reducing energy consumption of network infrastructure nodes in a wireless network, wherein the wireless network comprises the network infrastructure nodes and mobile terminal nodes comprising a receiver and a transmitter, wherein the network infrastructure nodes are mounted at fixed locations and are powered by an autonomous yet limited power supply and wherein the mobile terminal nodes are mobile with respect to the network infrastructure nodes and are configured to communicate with the network infrastructure nodes, the method comprising, for each of the network infrastructure nodes:

a) turning a transmitter and a receiver of the network infrastructure node to a power-off state;

b) powering-on the transmitter of the network infrastructure node for a limited transmission time frame;

c) during the transmission time frame, transmitting a beacon message comprising an identifier of the network infrastructure node, channel characteristics of the network infrastructure node and a powering-on schedule of the receiver of the network infrastructure node, for allowing mobile terminal nodes in the network to communicate with the network infrastructure node at least during a limited time frame in accordance with the schedule, wherein the power consumption of network infrastructure nodes is significantly reduced at the expense of using more power consumption in mobile terminal nodes by almost continuously maintaining the receiver of the mobile terminal nodes in a power-on state;

d) powering-on the receiver of the network infrastructure node and the transmitter of the mobile terminal nodes during a limited reception time frame in accordance with the schedule received by the mobile terminal node, for enabling the receiver of the network infrastructure node to receive messages transmitted by the mobile terminal nodes in the network if required;

e) repeating steps a) to d) periodically.

2. The method as claimed in claim 1 , wherein the wireless network comprises a tracking wireless network.

3. The method as claimed in claim 1 , wherein the autonomous power supply is at least one battery, an energy harvesting mechanism, or a combination thereof.

4. The method as claimed in claim 1 , wherein the wireless network comprises an ad-hoc, multi-node wireless network.

5. The method as claimed in claim 1 , wherein the wireless network comprises a wireless sensor network.

6. A network infrastructure node in a wireless network, the wireless network comprising network infrastructure nodes mounted at fixed locations and being powered by an autonomous yet limited power supply, and mobile terminal nodes comprising a receiver and a transmitter which are mobile with respect to the network infrastructure nodes and which are configured to communicate with the network infrastructure nodes, the network infrastructure node comprising:

a transmitter;

a receiver;

a processing unit operatively connected to the transmitter and the receiver and configured to turn the transmitter and the receiver of the network infrastructure node to a power-off state, to power-on the transmitter of the network infrastructure node for a limited transmission time frame, to transmit, during the transmission time frame, a beacon message comprising an identifier of the network infrastructure node, channel characteristics of the network infrastructure node and a powering-on schedule of the receiver of the network infrastructure node for allowing mobile terminal nodes in the network to communicate with the network infrastructure node at least during a limited time frame in accordance with the schedule received from at least one of the network infrastructure nodes, the transmitter of the mobile terminal nodes being powered-on in accordance with the schedule received from at least one of the network infrastructure nodes and to power-on the receiver of the network infrastructure node during a limited reception time frame in accordance with the schedule for enabling the receiver of the network infrastructure node to receive messages transmitted by the mobile terminal nodes in the network if required, wherein the power consumption of network infrastructure nodes is significantly reduced at the expense of using more power consumption in mobile terminal nodes by almost continuously maintaining the receiver of the mobile terminal nodes in a power-on state;

an autonomous yet limited power supply for supplying power to the transmitter, the receiver and the processing unit.

7. The network infrastructure node as claimed in claim 6 , wherein the wireless network comprises a tracking wireless network.

8. The network infrastructure node as claimed in claim 6 , wherein the autonomous power supply is at least one battery, an energy harvesting mechanism, or a combination thereof.

9. The network infrastructure node as claimed in claim 6 , wherein the wireless network comprises an ad-hoc, multi-node wireless network.

10. The network infrastructure node as claimed in claim 6 , wherein the wireless network comprises a wireless sensor network.

11. A wireless network comprising a plurality of network infrastructure nodes and a plurality of mobile terminal nodes, the wireless network being configured to reduce energy consumption of the network infrastructure nodes at the expense of using more energy consumption of the mobile terminal nodes by almost continuously maintaining the receiver of the mobile terminal nodes in a power-on state, most of the network infrastructure nodes being powered by an autonomous yet limited power supply, the network infrastructure nodes being mounted at fixed locations, the mobile terminal nodes being mobile with respect to the network infrastructure nodes, the mobile terminal nodes being configured to communicate with the network infrastructure nodes, wherein the network infrastructure nodes are configured to be continuously in a power-off state except during prescheduled reception and transmission time frames, and wherein mobile terminal nodes are configured to be almost continuously in a power-on state, wherein the mobile terminal nodes and the network infrastructure nodes exchange messages therebetween at least during a limited time frame in accordance with the schedule in order for each mobile terminal node to be connected to one network infrastructure node in the network.

12. The wireless network as claimed in claim 11 , wherein the wireless network is a tracking wireless network.

13. The wireless network as claimed in claim 11 , wherein the autonomous power supply is at least one battery, an energy harvesting mechanism, or a combination thereof.

14. The wireless network as claimed in claim 11 , wherein the wireless network comprises an ad-hoc, multi-node wireless network.

15. The wireless network as claimed in claim 11 , wherein the wireless network comprises a wireless sensor network.

16. A non-transitory computer-readable medium containing instructions for controlling at least one processor to perform a method of reducing energy consumption in an autonomously powered network infrastructure node in a wireless network comprising network infrastructure nodes and mobile terminal nodes comprising a receiver and a transmitter, wherein the network infrastructure nodes are mounted at fixed locations and are powered by an autonomous yet limited power supply, and wherein the mobile terminal nodes are mobile with respect to the network infrastructure nodes and are configured to communicate with the network infrastructure nodes, the method comprising:

a) turning a transmitter and a receiver of the network infrastructure node to a power-off state;

b) powering-on the transmitter of the network infrastructure node for a limited transmission time frame;

c) during the transmission time frame, transmitting a beacon message comprising an identifier of the network infrastructure node, channel characteristics of the network infrastructure node and a powering-on schedule of the receiver of the network infrastructure node, for allowing mobile terminal nodes in the network to communicate with the network infrastructure node at least during a limited time frame in accordance with the schedule, wherein the power consumption of network infrastructure nodes is significantly reduced at the expense of using more power consumption in mobile terminal nodes by almost continuously maintaining the receiver of the mobile terminal nodes in a power-on state;

d) powering-on the receiver of the network infrastructure node and the transmitter of the mobile terminal nodes during a limited reception time frame in accordance with the schedule, for enabling the receiver to receive messages transmitted by the mobile terminal nodes in the network if required;

e) repeating steps a) to d) periodically.

17. A method as claimed in claim 1 , further comprising the step of:

f) transmitting a connect/disconnect message to a central server connected to at least one of the network infrastructure nodes based on a presence/absence of exchange of messages between the mobile terminal nodes and the network infrastructure nodes.

18. A method as claimed in claim 17 , wherein the transmission of connect/disconnect messages to the central server is done via the network infrastructure nodes.

19. A method as claimed in claim 1 , wherein the energy consumption of the mobile terminal nodes is not minimized.

20. A method as claimed in claim 11 , wherein the energy consumption of the mobile terminal nodes is not minimized.