Wireless communications system and method
View Patent ↗A wireless communications system includes a base station, a plurality of intermediate devices, and a terminal device. Downlink communications may be provided directly from the base station to the terminal device, including control signals which instruct the terminal device where to send uplink data. This enables the base station to directly control scheduling of uplink communications, and in particular to define an uplink route from the terminal device to the base station via one or more intermediate devices. Power is conserved at the terminal device on the uplink because a lower power transmission can be used which although insufficient to reach the base station can reach the intermediate device. The terminal device is not required to determine the uplink path itself and therefore does not require complex, expensive, and power consuming control logic.
1. A terminal device for wirelessly communicating data to and from a base station via one or more of a plurality of intermediate devices within a wireless communications system, the terminal device comprising:
reception circuitry configured to wirelessly receive, directly from the base station, downlink signals including terminal control signals that identify a target device to which the terminal device is to direct uplink signals intended for the base station, the target device being one of the intermediate devices; and
transmission circuitry configured to wirelessly transmit the uplink signals to the target device for subsequent transmission to the base station, wherein
the reception circuitry is further configured to
receive an acknowledgement message from the target device, the acknowledgement message indicating that the uplink signal is successfully received by the target device, and
receive, directly from the base station, a second acknowledgement message indicating that the uplink signal is successfully received by the base station.
2. The terminal device according to claim 1 , wherein the terminal control signals comprise scheduling information having a plurality of address fields, each of the address fields comprising a transmitter address field identifying the terminal device and a receiver address field identifying the target device.
3. The terminal device according to claim 2 , wherein the address fields are radio network temporary identifiers (RNTIs) specified on a physical downlink control channel (PDCCH) broadcast by the base station.
4. The terminal device according to claim 3 , wherein the control signals comprise scheduling information specifying one or more of a transmission power, data rate, transmission frequency, transmission timeslot and number of resource blocks for the uplink signals.
5. The terminal device according to claim 1 , wherein the terminal device serves as an intermediate device in relation to uplink communications from another terminal device to the base station.
6. The terminal device according to claim 1 , wherein the uplink signals and the downlink signals are machine type communication (MTC).
7. The terminal device according to claim 1 , wherein the target device receives the uplink signals from the terminal device and transmits the uplink signals to a second intermediate device for subsequent transmission to the base station.
8. The terminal device according to claim 1 , wherein each intermediate device of the plurality of intermediate devices is as relay node, and the target device is a target relay node.
9. A method of wirelessly communicating data between a terminal device and a base station via one or more of a plurality of intermediate devices within a wireless communications system, the method comprising:
wirelessly receiving downlink signals from the base station, by reception circuitry of the terminal device, the downlink signals including terminal control signals that identify a target device to which the terminal device is to direct uplink signals intended for the base station, the target device being one of the intermediate devices;
wirelessly transmitting the uplink signals to the target device, by transmission circuitry of the terminal device, for subsequent transmission to the base station;
receiving an acknowledgement message from the target device, the acknowledgement message indicating that the uplink signal is successfully received by the target device; and
receiving, directly from the base station, a second acknowledgement message indicating that the uplink signal is successfully received by the base station.
10. The method according to claim 9 , wherein the terminal control signals comprise scheduling information having a plurality of address fields, each of the address fields comprising a transmitter address field identifying the terminal device and a receiver address field identifying the target device.
11. The method according to claim 10 , wherein the address fields are radio network temporary identifiers (RNTIs) specified on a physical downlink control channel (PDCCH) broadcast by the base station.
12. The method according to claim 11 , wherein the control signals comprise scheduling information specifying one or more of a transmission power, data rate, transmission frequency, transmission timeslot and number of resource blocks for the uplink signals.
13. The method according to claim 9 , wherein the uplink signals and the downlink signals are machine type communication (MTC).
14. The method according to claim 9 , wherein the target device receives the uplink signals from the terminal device and transmits the uplink signals to a second intermediate device for subsequent transmission to the base station.
15. The method according to claim 9 , further comprising:
receiving, by the reception circuitry of the terminal device, second uplink communication from another terminal device; and
transmitting, by the transmission circuitry of the terminal device, the second uplink communication to the base station.
16. The method according to claim 9 , wherein each intermediate device of the plurality of intermediate devices is as relay node, and the target device is a target relay node.