1. A portable terminal communicating with a plurality of base stations by use of an orthogonal frequency division multiplexing (OFDM) signal, the portable terminal comprising:
a communication unit sending and receiving the OFDM signal to and from the base stations;
a switching timing detector detecting switching timing at which handover and a normal state are switched therebetween; and
an OFDM signal controller changing a guard time length of the OFDM signal upon detecting the timing by the switching timing detector.
2. The portable terminal according to claim 1, wherein the OFDM signal controller changes a symbol length of the OFDM signal and the guard time length upon detecting the switching timing by the switching timing detector.
3. The portable terminal according to claim 1, wherein the OFDM signal controller makes the guard time length longer than the current one when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
4. The portable terminal according to claim 1, wherein the OFDM signal controller increases the guard time length and the symbol length when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
5. The portable terminal according to claim 1, wherein the OFDM signal controller increases the guard time length and makes the symbol length by an amount of time corresponding to an increase in the guard time length when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
6. The portable terminal according to claim 1, wherein the OFDM signal controller changes the symbol length to a value n times as great as currently set symbol length, where n is an integer, when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
7. The portable terminal according to claim 6, wherein the integer is two.
8. The portable terminal according to claim 1, further comprising:
a timing difference measurer measuring a timing difference between two OFDM signals received by the communication unit from two base stations during the handover, respectively; and
a length determiner, based on the timing difference measured by the timing difference measurer, determining a value of the guard time length to be changed by the OFDM signal controller, wherein
the OFDM signal controller changes the guard time to the value determined by the length determiner when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
9. The portable terminal according to claim 8, further comprising a guard time length table in which the timing difference and the value of the guard time length to be set for the OFDM signal are associated with each other, wherein
the length determiner determines, as a value of the guard time length to be changed by the OFDM signal controller, the value of the guard time length associated with the timing difference measured by the timing difference measurer in the guard time length table.
10. The portable terminal according to claim 1, wherein
the communication unit receives from the base stations guard time length information indicating a value of the guard time length during the handover; and
the OFDM signal controller changes the guard time length to a value indicated by the guard time length information received by the communication unit when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
11. The portable terminal according to claim 1, wherein
the switching timing detector detects handover completion timing at which the handover is switched to the normal state; and
the OFDM signal controller makes the guard time length of the OFDM signal shorter than currently set guard time length when the switching timing detector detects the handover complete timing.
12. The portable terminal according to claim 1, further comprising a spreading rate determiner determining a spreading rate of the OFDM signal based on a value of the guard time length changed by the OFDM signal controller.
13. The portable terminal according to claim 12, wherein the spreading rate determiner makes the spreading rate lower than currently set spreading rate when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
14. The portable terminal according to claim 12, wherein the spreading rate determiner changes the spreading rate to a value 1n of currently set spreading rate, where n is an integer, when the switching timing detector detects handover start timing at which the normal state is switched to the handover.
15. The portable terminal according to claim 14, wherein the integer is two.
16. A communication system in which a plurality of base stations and a portable terminal communicate with each other by use of an OFDM signal, wherein
the portable terminal comprises
a communication unit sending and receiving the OFDM signal to and from the base stations;
a switching timing detector detecting switching timing at which handover and a normal state are switched therebetween; and
an OFDM signal controller changing a guard time length of the OFDM signal upon detecting the switching timing by the switching timing detector; and
the base stations each change, at the same time as the OFDM signal controller changes the guard time length, the guard time length to the same length as that changed by the OFDM signal controller.
17. A method of communicating with a base station by a portable terminal, the method comprising:
sending and receiving an OFDM signal to and from the base station;
detecting switching timing at which handover and a normal state are switched therebetween; and
changing a guard time length of the OFDM signal when the switching timing is detected.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method, for attracting together individuals using a plurality of wireless communications devices, comprising:
receiving, by a system using a processor, from a first wireless communications device of the plurality of wireless communications devices, a request to generate an attractor to be made availabe to other wireless communications devices of the plurality of wireless communications devices;
obtaining, by the system, a first location, of the first wireless communications device;
identifying, by the system, an event area corresponding to the first location;
identifying, by the system, a predefined subscriber group, of multiple predefined subscriber groups, associated with the event area identified;
generating, by the system, the attractor being for the predefined subscriber group and associated with the event area;
obtaining, by the system, a second location, of a second wireless communications device of the plurality of wireless communications devices;
making available, by the system, to the second wireless communications device, in response to determining that the event area includes the second location, the attractor corresponding to the predefined subscriber group and to the event area; and
making available, by the system, to the second wireless communications device, instructions for finding a group location corresponding to the predefined subscriber group.
2. The method of claim 1, further comprising:
receiving, from the second wireless communications device, a response to the attractor; and
sending, to the first wireless communications device, a communication indicating the response to the attractor received from the second wireless communications device.
3. The method of claim 2, wherein the communication indicates progress in finding the group location.
4. The method of claim 1, wherein the event area corresponds to a pre-defined event held periodically at the event area.
5. The method of claim 1, wherein making available, by the system, the instructions for finding the group location comprises making available information having an indication that a group meeting point will be changed.
6. The method of claim 1, wherein making available, to the second wireless communications device, the attractor corresponding to the predefined subscriber group and to the event area comprises sending the attractor to the second wireless communications device.
7. The method of claim 1, wherein making available, to the second wireless communications device, the attractor corresponding to the predefined subscriber group and to the event area comprises permitting access to the attractor for the second wireless communications device.
8. The method of claim 1, wherein making available, to the second wireless communications device, the instructions for finding the group location comprises sending the instructions to the second wireless communications device.
9. The method of claim 8, wherein sending the instructions is performed in response to receiving a request sent by the second wireless communications device in response to receipt of the attractor at the second wireless communications device.
10. The method of claim 8, wherein sending the instructions to the second wireless communications device comprises sending the instructions as part of sending the attractor to the second wireless communications device.
11. The method of claim 1, wherein making available, to the second wireless communications device, the instructions for finding the group location comprises permitting access to the instructions for the second wireless communications device.
12. The method of claim 11, wherein making available the instructions is performed in response to receiving a request sent by the second wireless communications device in response to receipt of the attractor at the second wireless communications device.
13. The method of claim 1, wherein, in making available instructions for finding the group location, the group location is the first location.
14. The method of claim 1, wherein:
the processor of the system is in operative communication with a database; and
the event area identified is associated in the database with the predetermined subscriber group and with subscribed members of the group, including the second wireless communications device.
15. The method of claim 1, further comprising determining, by the system, that the first wireless communications device is subscribed as a member of the predetermined subscriber group.
16. The method of claim 1, wherein the generating is performed in response to determining that the first wireless communications device is a subscribed member of the predetermined subscriber group.
17. The method of claim 1, further comprising:
prompting a user of the second wireless communications device for a password defined for the predetermined subscriber group associated with the attractor generated; and
receiving the password from the second wireless communications device;
wherein making the instructions available to the second wireless communications device is performed in response to receiving the password from the second wireless communications device.
18. A computer-readable storage device comprising computer-executable instructions that, when executed by a processor, cause the processor to perform operations, for attracting together individuals using a plurality of wireless communications devices, comprising:
receiving from a first wireless communications device of the plurality of wireless communications devices, a request to generate an attractor to be made available to other wireless communications devices of the plurality of wireless communications devices;
obtaining a first location, of the first wireless communications device;
identifying an event area corresponding to the first location;
identifying a predefined subscriber group, of multiple predefined subscriber groups, associated with the event area identified;
generating the attractor being for the predefined subscriber group and associated with the event area;
obtaining a second location, of a second wireless communications device of the plurality of wireless communications devices;
making available, by the system, to the second wireless communications device, in response to determining that the event area includes the second location, the attractor corresponding to the predefined subscriber group and to the event area; and
making available to the second wireless communications device, instructions for finding a group location corresponding to the predefined subscriber group.
19. The computer-readable storage device of claim 18, wherein the operation of making available, to the second wireless communications device, the attractor corresponding to the predefined subscriber group and to the event area comprises a function selected from a group consisting of:
sending the attractor to the second wireless communications device; and
permitting access to the attractor for the second wireless communications device.
20. The computer-readable storage device of claim 18, wherein the operation of making available, to the second wireless communications device, the instructions for finding the group location comprises a function selected from a group consisting of:
sending the instructions to the second wireless communications device; and
permitting access to the instructions for the second wireless communications device.
21. A system comprising:
a processor; and
a computer-readable storage device comprising computer-executable instructions that, when executed by a processor, cause the processor to perform operations, for attracting together individuals using a plurality of wireless communications devices, comprising:
receiving from a first wireless communications device of the plurality of wireless communications devices, a request to generate an attractor to be made available to other wireless communications devices of the plurality of wireless communications devices;
obtaining a first location, of the first wireless communications device;
identifying an event area corresponding to the first location;
identifying a predefined subscriber group, of multiple predefined subscriber groups, associated with the event area identified;
generating the attractor being for the predefined subscriber group and associated with the event area;
obtaining a second location, of a second wireless communications device of the plurality of wireless communications devices;
making available, by the system, to the second wireless communications device, in response to determining that the event area includes the second location, the attractor corresponding to the predefined subscriber group and to the event area; and
making available to the second wireless communications device, instructions for finding a group location corresponding to the predefined subscriber group.