Overlay of bearers in a radio communication system
A radio system having multiple bearers overlays a relatively narrowband bearer such as P25 on a relatively wideband bearer such as LTE, for transmission of both uplink and downlink signals. The wideband bearer uses a spectrum of subcarriers which form a set of radio frequency blocks. One or more blocks or other related parts of the spectrum may be allocated to the narrowband bearer. In some cases the narrowband bearer may push through the wideband allocation using a relatively high power to dominate signals transmitted by the wideband bearer. Voice calls such as emergency calls using the narrowband bearer may be prioritized.
1. A method of providing services to users in a mobile radio system having base stations that transmit radio downlink signals and user terminals that transmit radio uplink signals, the base stations comprising:
one or more first base stations provided for a wideband bearer operating in accordance with a first standard for wireless communications;
one or more second base stations, separate from the one or more first base stations, provided for a narrowband bearer operating in accordance with a second standard for wireless communications, the second standard being different from the first standard, wherein the method comprising:
allocating one or more radio frequency blocks for transmission of the downlink signals or the uplink signals using the wideband bearer;
allocating one or more radio frequency blocks for transmission of the
downlink signals or the uplink signals using the narrowband bearer;
maintaining a database which contains frequency block allocation information for the wideband and narrowband bearers;
selectively re-allocating one or more frequency blocks from the wideband bearer to the narrowband bearer according to demand for services using the narrowband bearer;
selectively re-allocating one or more frequency blocks from the narrowband bearer to the wideband bearer according to demand for services using the wideband bearer; and
updating the database with frequency block re-allocation information.
2. The method according to claim 1 wherein un-used frequency blocks are re-allocated from the wideband bearer to the narrowband bearer when all traffic channels available to the narrowband bearer are in use.
3. The method according to claim 1 wherein un-used frequency blocks are re-allocated from the narrowband bearer to the wideband bearer when all traffic channels available to the wideband bearer are in use.
4. The method of claim 1 wherein the wideband bearer operates according to the Long-Term Evolution (LTE) standard and the narrowband bearer operates according to the Project 25 (P25), Digital Mobile Radio (DMR) or Land Mobile Radio (LMR) standard.
5. The method of claim 1 wherein frequency blocks initially allocated for transmission of signals using the wideband bearer lie within the range 758 to 768 MHz.
6. The method of claim 1 wherein frequency blocks re-allocated from the narrowband bearer to the wideband bearer lie within the range 769 to 775 MHz.
7. The method of claim 1 wherein frequency blocks initially allocated for transmission of signals using the narrowband bearer lie within the range 769 to 775 MHz.
8. The method of claim 1 wherein frequency blocks re-allocated from the wideband bearer to the narrowband bearer lie within the range 758 to 768 MHz.
9. The method of claim 1 wherein voice calls over the mobile radio system always uses the narrowband bearer if possible.
10. A controller for a mobile radio system with multiple wireless bearers, having base stations that transmit radio downlink signals and user terminals that transmit radio uplink signals, the base stations comprising:
(i) one or more first base stations provided for a wideband bearer operating in accordance with a first standard for wireless communications, and
(ii) one or more second base stations, separate from the one or more first base stations, provided for a narrowband bearer operating in accordance with a second standard for wireless communications, the second standard being different from the first standard;
the controller having a processor and memory, the memory containing instructions that cause the controller to:
allocate one or more radio frequency blocks for transmission of the downlink signals or the uplink signals using the wideband bearer;
allocate one or more radio frequency blocks for transmission of the downlink signals or the uplink signals using the narrowband bearer;
maintain a database which contains frequency block allocation information for the wideband and narrowband bearers;
selectively re-allocate one or more frequency blocks from the wideband bearer to the narrowband bearer according to demand for services using the narrowband bearer;
selectively re-allocate one or more frequency blocks from the narrowband bearer to the wideband bearer according to demand for services using the wideband bearer; and
update the database with frequency block re-allocation information.
11. The controller of claim 10 wherein un-used frequency blocks are re-allocated from the wideband bearer to the narrowband bearer when all traffic channels available to the narrowband bearer are in use.
12. The controller of claim 10 wherein un-used frequency blocks are re-allocated from the narrowband bearer to the wideband bearer when all traffic channels available to the wideband bearer are in use.
13. The controller of claim 10 wherein the wideband bearer operates according to the Long-Term Evolution (LTE) standard and the narrowband bearer operates according to the Project 25 (P25), Digital Mobile Radio (DMR) or Land Mobile Radio (LMR) standard.
14. The controller of claim 10 wherein frequency blocks initially allocated for transmission of signals using the wideband bearer lie within the range 758 to 768 MHz.
15. The controller of claim 10 wherein frequency blocks re-allocated from the narrowband bearer to the wideband bearer lie within the range 769 to 775 MHz.
16. The controller of claim 10 wherein frequency blocks initially allocated for transmission of signals using the narrowband bearer lie within the range 769 to 775 MHz.
17. The controller of claim 10 wherein frequency blocks re-allocated from the wideband bearer to the narrowband bearer lie within the range 758 to 768 MHz.
18. The controller of claim 10 wherein voice calls over the mobile radio system always uses the narrowband bearer if possible.