Synchronization method in a frequency hopping local area network having dedicated control channels
First Claim
1. In a frequency hopping communication system having a plurality of cells, each cell having a hopping sequence comprising an ordered set of data frequencies, and further comprised of a central controller in communication with a plurality of user devices, a method for a user device to acquire synchronization with one of the plurality of cells, comprising the steps of:
- at the central controllers;
providing a set of synchronizing frequencies different from the data frequencies;
informing user devices of the synchronizing frequencies;
transmitting user data and first synchronization information at a data frequency during respective portions of a long dwell; and
transmitting second synchronization information at a synchronizing frequency during a portion of a short dwell, wherein the short dwells are interleaved between the long dwells;
at the user device and upon a decision to acquire synchronization;
tuning to at least one of the synchronizing frequencies and receiving second synchronization information;
processing the received second synchronization information to select a central controller based on the receipt of the second synchronization information; and
employing the hopping sequence and interleave pattern used by the selected central controller to commence communication.
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Abstract
A method for a synchronizing user devices (12) performing handoffs includes providing a set of location synchronizing frequencies and data frequencies selected from a hopping set used by network access points (14). Each AP transmits synchronizing data (36) at the synchronizing frequencies during a portion of a short dwell (32), the short dwells (32) being interleaved between long dwells (30). When a user device (12) attempt a handoff, it tunes to at least one of the synchronizing frequencies and receives synchronizing information (36). The user device (12) then selects one AP (14) for link transfer and synchronizes its operation to the hopping set used by the selected AP (14).
99 Citations
15 Claims
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1. In a frequency hopping communication system having a plurality of cells, each cell having a hopping sequence comprising an ordered set of data frequencies, and further comprised of a central controller in communication with a plurality of user devices, a method for a user device to acquire synchronization with one of the plurality of cells, comprising the steps of:
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at the central controllers; providing a set of synchronizing frequencies different from the data frequencies; informing user devices of the synchronizing frequencies; transmitting user data and first synchronization information at a data frequency during respective portions of a long dwell; and transmitting second synchronization information at a synchronizing frequency during a portion of a short dwell, wherein the short dwells are interleaved between the long dwells; at the user device and upon a decision to acquire synchronization; tuning to at least one of the synchronizing frequencies and receiving second synchronization information; processing the received second synchronization information to select a central controller based on the receipt of the second synchronization information; and employing the hopping sequence and interleave pattern used by the selected central controller to commence communication. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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Specification