Communication apparatus enabling coexistence of systems
A frequency band is divided into N subchannels. Sub-channels are first allocated for a power line communication system having a higher priority, such as public communication or the like. Sub-channels for a power line communication system having a relatively low priority, such as in-home communication or the like, are allocated from free subchannels. In this case, the subchannels used by the power line communication system having the high priority are limited to a plurality of consecutive subchannels from an upper side or a lower side of the frequency band.
1. A first communication apparatus that belongs to a first communication system having a highest-priority with respect to using a frequency band including a first sub-frequency band and a second sub-frequency band, the first communication system being one of a plurality of communication systems coexisting on the same communication medium, each of the plurality of communication systems having a given predetermined priorities with respect to using the frequency band, an upper limit and a lower limit of the frequency band being respectively defined as F_MAX and F_MIN, the first communication apparatus comprising:
a coexistence signal generator that selects, out of a plurality of candidates, F_BOUND 1 which is an upper limit of the first sub-frequency band which is used by the first communication system, and generates a coexistence signal indicating the first sub-frequency band from F_MIN to F_BOUND 1 is occupied and used by the first communication system, F_BOUND 1 being higher than F_MIN and F_BOUND 1 being lower than F_MAX; and
a coexistence signal transmitter that transmits the coexistence signal to another communication system of the plurality of communication systems,
wherein the first sub-frequency band is usable by the first communication system or the other communication system, and the second sub-frequency band upper than the first sub-frequency band is usable only by the other communication system.
2. The first communication apparatus according to claim 1 , wherein
a period for data communication is divided into a plurality of time slots, and
the coexistence signal generator generates a coexistence signal having a matrix structure in which an occupied and used frequency band and a time slot are specified.
3. The first communication apparatus according to claim 1 , wherein the coexistence signal comprising: a time slot indicating whether or not the first sub-frequency band from F_MIN to F_BOUND 1 is used; and a time slot specifying a value of F_BOUND 1 when the frequency band from F_MIN to F_BOUND 1 is used.
4. The first communication apparatus according to claim 1 , wherein the communication medium used by the first communication system is a power line.
5. The first communication apparatus according to claim 1 , wherein the communication medium used by the first communication system is a wireless medium.
6. The first communication apparatus according to claim 1 , wherein
the first communication system is a system used as an access system, and the other communication system is a system used as an in-home system.
7. A second communication apparatus that belongs to a second communication system having other than a highest-priority with respect to using a frequency band including a first sub-frequency band and a second sub-frequency band, the second communication system being one of a plurality of communication systems coexisting on the same communication medium, each of the plurality of communication systems having a given predetermined priorities with respect to using the frequency band, an upper limit and a lower limit of the frequency band being respectively defined as F_MAX and F_MIN, the second communication apparatus comprising:
a coexistence signal receiver that receives, from a first communication system having the highest-priority use right, a first coexistence signal indicating that the first sub-frequency band from F_MIN to F_BOUND 1 is occupied and used by the first communication system, F_BOUND 1 being selected by the first communication system, F_BOUND 1 being higher than F_MIN and F_BOUND 1 being lower than F_MAX, and
a frequency band determiner that determines a third sub-frequency band which is to be occupied and used by the second communication system, the third sub-frequency band which is included in the second sub-frequency band upper than the first sub-frequency band indicated by the first coexistence signal,
wherein the first sub-frequency band is usable by one of the first communication system, the second communication system, and the other communication system, and the second sub-frequency band is usable by one of communication systems other than the first communication system.
8. The communication apparatus according to claim 7 , further comprising
a coexistence signal generator that generates a second coexistence signal indicating the third sub-frequency band; and
a coexistence signal transmitter that transmits the second coexistence signal to a communication system other than the second communication system.
9. The second communication apparatus according to claim 7 , wherein a period for data communication is divided into a plurality of time slots.
10. The second communication apparatus according to claim 7 , wherein the second coexistence signal comprising: a time slot indicating whether or not the frequency band from F_MIN to F_BOUND 1 is used; and a time slot specifying a value of F_BOUND 1 when the frequency band from F_MIN to F_BOUND 1 is used.
11. The second communication apparatus according to claim 7 , wherein the communication medium used by the second communication system is a power line.
12. The second communication apparatus according to claim 7 , wherein the communication medium used by the second communication system is a wireless medium.
13. The second communication apparatus according to claim 7 , wherein
the first communication system is a system used as an access system, and each of the second communication system and the other communication system is a system used as an in-home system.
14. An integrated circuit used in a first communication apparatus that belongs to a first communication system having a highest-priority with respect to using a frequency band including a first sub-frequency band and a second sub-frequency band, the first communication system being one of a plurality of communication systems coexisting on the same communication medium, each of the plurality of communication systems having a given predetermined priorities with respect to using the frequency band, an upper limit and a lower limit of the frequency band being respectively defined as F_MAX and F_MIN, wherein
circuits functioning as the following sections are integrated on the integrated circuit:
a coexistence signal generating section that selects, out of a plurality of candidates, F_BOUND 1 which is an upper limit of the first sub-frequency band which is used by the first communication system, and generates a coexistence signal indicating the first sub-frequency band from F_MIN to F_BOUND 1 is occupied and used by the first communication system, F_BOUND 1 being higher than F_MIN and F_BOUND 1 being lower than F_MAX; and
a coexistence signal transmitting section that transmits the coexistence signal to another communication system of the plurality of communication systems,
wherein the first sub-frequency band is usable by the first communication system or the other communication system, and the second sub-frequency band upper than the first sub-frequency band is usable only by the other communication system.
15. An integrated circuit used in a second communication apparatus that belongs to a second communication system having other than a highest-priority with respect to using a frequency band including a first sub-frequency band and a second sub-frequency band, the second communication system being one of a plurality of communication systems coexisting on the same communication medium, each of the plurality of communication systems having a given predetermined priorities with respect to using the frequency band, an upper limit and a lower limit of the frequency band being respectively defined as F_MAX and F_MIN, wherein
circuits functioning as the following sections are integrated on the integrated circuit:
a coexistence signal receiving section that receives, from a first communication system having the highest-priority use right, a first coexistence signal indicating that the first sub-frequency band from F_MIN to F_BOUND 1 is occupied and used by the first communication system, F_BOUND 1 being selected by the first communication system, F_BOUND 1 being higher than F_MIN and F_BOUND 1 being lower than F_MAX; and
a frequency band determining section that determines a third sub-frequency band which is to be occupied and used by the second communication system, the third sub-frequency band which is included in the second sub-frequency band upper than the first sub-frequency band indicated by the first coexistence signal,
wherein the first sub-frequency band is usable by one of the first communication system, the second communication system, and the other communication system, and the second sub-frequency band is usable by one of communication systems other than the first communication system.
16. The second communication apparatus according to claim 8 , wherein the coexistence signal has a matrix structure in which an occupied and used frequency band and a time slot are specified.
17. A communication method used in a first communication system, having a highest-priority use right, of a plurality of communication systems, which are given predetermined priorities with respect to a right to use a frequency band of which an upper limit and a lower limit are respectively defined as F_MAX and F_MIN, coexist on the same communication medium, the method comprising:
selecting, out of a plurality of candidates, F_BOUND 1 which is an upper limit of the first sub-frequency band which is used by the first communication system;
generating a coexistence signal indicating the first sub-frequency band from F_MIN to F_BOUND 1 is occupied and used by the first communication system, F_BOUND 1 being higher than F_MIN and F_BOUND 1 being lower than F_MAX; and
transmitting the coexistence signal to another communication system of the plurality of communication systems,
wherein the first sub-frequency band is usable by the first communication system or the other communication system, and the second sub-frequency band upper than the first sub-frequency band is usable only by the other communication system.
18. A communication method used in a first communication system, having a use right other than a highest-priority use right, of a plurality of communication systems, which are given predetermined priorities with respect to a right to use a frequency band of which an upper limit and a lower limit are respectively defined as F_MAX and F_MIN, coexist on the same communication medium, the method comprising:
receiving, from a first communication system having the highest-priority use right, a first coexistence signal indicating a frequency band from F_MIN to F_BOUND 1 , F_BOUND 1 being selected by the first communication system, F_BOUND 1 being higher than F_MIN and F_BOUND 1 being lower than FMAX, which is occupied and used by the first communication system; and
determining a third sub-frequency band which is to be occupied and used by the second communication system, the third sub-frequency band which is included in the second sub-frequency band upper than the first sub-frequency band indicated by the first coexistence signal,
wherein the first sub-frequency band is usable by one of the first communication system, the second communication system, and the other communication system, and the second sub-frequency band is usable by one of communication systems other than the first communication system.