| US 7,577,434 B2 | ||
| Handover method in wireless LAN by assigning an identification code to a mobile station | ||
| Yoshihisa Nakano, Saitama (Japan); Hiroyuki Akiyama, Tokyo (Japan); and Takashi Namura, Tokyo (Japan) | ||
| Assigned to Oki Semiconductor Co., Ltd., (Japan) | ||
| Filed on Mar. 22, 2006, as Appl. No. 11/385,918. | ||
| Claims priority of application No. 2005-087498 (JP), filed on Mar. 25, 2005. | ||
| Prior Publication US 2006/0251021 A1, Nov. 09, 2006 | ||
| Int. Cl. H04W 36/00 (2009.01); H04W 4/00 (2009.01); H04B 7/00 (2006.01) | ||
| U.S. Cl. 455—436 [455/438; 370/332] | 8 Claims |
| 1. A handover method in a wireless local area network (LAN) including a first access point that controls wireless communications
with mobile stations existing in a first wireless area and a second access point that controls wireless communications with
mobile stations existing in a second wireless area, the first and second wireless area partially overlapping each other, comprising
the steps of:
assigning, when the first access point is requested by first one of the stations existing in the first wireless area for an
association with the wireless LAN, a first identification code different from an identification code assigned to another of
the stations which is already associated with the wireless LAN to approve the association;
assigning, when the second access point is requested by second one of the stations existing in the second wireless area for
an association with the wireless LAN, a second identification code different from an identification code assigned to another
of the stations which is already associated with the wireless LAN to approve the association;
periodically transmitting from the first or second access point a beacon frame to the first or second station existing and
associated in the first or second wireless areas, respectively, the beacon frame containing an identification code corresponding
to the first or second station;
monitoring by the first access point a signal received from the first station existing in the first wireless area;
requesting, when the first access point detects the received signal being lower than a predetermined level, the second access
point for a handover of the first station;
determining, when the second access point is requested for the handover from the first access point, whether to accept the
handover based on a signal received from the first station;
accepting the handover of the first station by the second access point; and
periodically transmitting from the second access point, in place of the first access point, a beacon frame containing the
first identification code assigned to the first station;
wherein the first or second access point assigns, when approving the association of the first or second station, the first
or second station to an identification code provided to the first or second access point, respectively,
each of the first and second access points comprising: an identification code manager for managing whether the identification
code is unassigned or assigned; and a station manager for managing correspondence of the first or second station of which
the association is approved with the identification code assigned to the first or second station, respectively.
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