Base station based methods and apparatus for supporting break before make handoffs in a multi-carrier system
First Claim
1. A method of operating a second network point of attachment in a communications system including a first network point of attachment, the first network point of attachment using signals in a first frequency band to communicate with a mobile node having a communications link with said first network point of attachment over which data can be communicated, the method comprising:
- transmitting beacon signals having a predetermined frequency into said first frequency band on a periodic basis, said first frequency band being a frequency band into which said second network attachment point does not transmit user data; and
using a second frequency band which is different from said first frequency band for establishing and maintaining communications links with mobile nodes over which user data can be communicated, said step of using a second frequency band including assigning segments of an uplink communications channel to mobile nodes, the uplink communications channel having a structure that includes a periodic repeating pattern of access segments and traffic segments, access segments being segments into which mobile nodes that do not have an existing wireless communication link established with said second network attachment point can send at least one signal to said network attachment point over the air to establish a wireless communications link with the second network attachment point, each access segment occurring at a fixed time offset from the point at which one of said beacon signals is transmitted into said first frequency band by said second network attachment point.
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Accused Products
Abstract
A mobile communications device initiates a handoff from its current base station (BS) sector network attachment point to a new BS sector. The mobile sends a handoff request over its current wireless link to the current BS sector, which forwards the request to the new BS sector, e.g., via a network link. The new BS sector processes the request assigning dedicated resources, e.g., an identifier and dedicated uplink segments. Information identifying the allocated resources is conveyed from the new BS sector via the current BS sector to the mobile. The mobile determines the time of the allocated dedicated segments based upon a received beacon signal from the new BS sector with known timing relationships to dedicated segments. The mobile breaks the original wireless link just prior to the time of the first assigned dedicated segment. The mobile communicates information on the assigned dedicated segments to perform registration operations, e.g., timing synchronization and power control, establishing a new wireless link.
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Citations
35 Claims
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1. A method of operating a second network point of attachment in a communications system including a first network point of attachment, the first network point of attachment using signals in a first frequency band to communicate with a mobile node having a communications link with said first network point of attachment over which data can be communicated, the method comprising:
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transmitting beacon signals having a predetermined frequency into said first frequency band on a periodic basis, said first frequency band being a frequency band into which said second network attachment point does not transmit user data; and
using a second frequency band which is different from said first frequency band for establishing and maintaining communications links with mobile nodes over which user data can be communicated, said step of using a second frequency band including assigning segments of an uplink communications channel to mobile nodes, the uplink communications channel having a structure that includes a periodic repeating pattern of access segments and traffic segments, access segments being segments into which mobile nodes that do not have an existing wireless communication link established with said second network attachment point can send at least one signal to said network attachment point over the air to establish a wireless communications link with the second network attachment point, each access segment occurring at a fixed time offset from the point at which one of said beacon signals is transmitted into said first frequency band by said second network attachment point. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of operating a second base station to perform a mobile node handoff operation involving a handoff of a mobile node from a first base station having a first communications link with said mobile node, the method comprising:
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allocating a dedicated resource to be used by said mobile node when establishing a second communications link with said second base station;
transmitting information about the dedicated resource to said first base station by a communications link between said first and second base stations;
receiving a timing control signal over the air from said mobile node in an uplink communications segment dedicated to said mobile node by said second base station; and
transmitting to said mobile node, after receiving said timing control signal, a timing synchronization signal, prior to receiving user data from said mobile node. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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23. A base station capable of performing mobile node handoff operations involving a handoff of a mobile node from another base station having a first communications link with said mobile node to said base station, the base station comprising:
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means for allocating a dedicated resource to be used by said mobile node when establishing a second communications link with said second base station;
means for transmitting information about the dedicated resource to said first base station of a communications link between said first and second base stations;
means for receiving a registration signal over the air from said mobile node; and
means for transmitting to said mobile node, after receiving said registration signal, a timing synchronization signal, prior to receiving user data from said mobile node. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
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31. A method of operating a base station to implement a mobile node handoff between a first link with a first base station sector, said first link using a first carrier, and a second link with a second base station sector said second link using a second carrier, the first and second sectors being within the same base station, at least the first sector being different from the second sector or the first carrier being different from the second carrier, the method comprising:
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transmitting a timing correction signal to said mobile node over said first communications link;
receiving from the mobile node a signal communicated over said first link indicating an intent to handoff to said second link;
transmitting over said first link information indicating a dedicated resource to be used by said mobile when communicating over said second communications link;
terminating said first communications link with said mobile node; and
receiving from said mobile node at least one of user data and a non-timing control signal over said second communications link prior to transmitting a transmission timing control adjustment signal generated based on any timing control signal received over said second communications link from said mobile node. - View Dependent Claims (32, 33, 34, 35)
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Specification