Abstract: Session signaling register message transmission methods and apparatus well suited for use in a communication system which supports mobile nodes capable of moving between domains and access nodes in a domain are described. Broadcasting of session signaling register messages is supported to reduce the number of registration messages which need to be transmitted between a mobile node and an access node. A paging and location server is used to reduce the number of session signaling register messages transmitted between domains. A visiting node registers with a paging and location server. The session signaling address of the paging and location server being used by a visiting mobile node is registered with the visiting node's home session signaling server. As the visiting node moves between access nodes in the visited domain the paging and location server it uses remains the same eliminating the need to update the home session signaling servers.

Abstract: Techniques for implementing message passing decoders, e.g., LDPC decoders, are described. To facilitate hardware implementation messages are quantized to integer multiples of ½ ln2. Messages are transformed between more compact variable and less compact constraint node message representation formats. The variable node message format allows variable node message operations to be performed through simple additions and subtractions while the constraint node representation allows constraint node message processing to be performed through simple additions and subtractions. Variable and constraint nodes are implemented using an accumulator module, subtractor module and delay pipeline. The accumulator module generates an accumulated message sum. The accumulated message sum for a node is stored and then delayed input messages from the delay pipeline are subtracted there from to generate output messages.

Abstract: Group communications methods and apparatus are described. In particular, methods for granting a mobile device access to a communications resource, e.g., the right to transmit data, associated with a group are described. User requests for the communications resource are suppressed by the corresponding mobile device, for periods during which the communications resource has been granted to another mobile device. A mobile device may store a suppressed user request so that a resource request signal may be transmitted after the communications resource has been released by the mobile device that was previously granted the resource. In this manner requests that cannot be granted are not transmitted, increasing communications efficiency as compared to systems where requests are not suppressed at the mobile devices. A priority scheme is used in some embodiments to determine whether or not a request should be suppressed while another device has been granted the communications resource.

Abstract: Methods and apparatus for storing, manipulating, retrieving, and forwarding state, e.g., context and other information, used to support communications sessions with one or more end nodes, e.g., mobile devices, are described. Various features are directed to a mobile node controlling the transfer of state from a first access node to a second access node during a handoff operation thereby eliminating any need for state transfer messages to be transmitted between the second access node and the first access node during handoff. Other features of the invention are directed to the use of a core network node to store state information. State information stored in the core node can be accessed and used by access nodes in cases where a mobile node does not send a state transfer message during a handoff, e.g., because communication with the first access node is lost or because such messages are not supported.

Abstract: Methods and apparatus for splitting Golay sequences into a plurality of subsets of sequence elements and transmitting the subsets are described. The sequence subsets include an equal number of elements, e.g., symbols, from the split sequence and are transmitted using one group of tones per subset. The tones in each group of tones are uniformly spaced with one symbol being transmitted on each tone. The groups of tones are separated from one another by a frequency spacing which is greater, e.g., many times greater, than the frequency spacing between the tones in each group. Low peak to average power ratios are achieved for the transmitted signals while at the same time allowing for a wide band of frequencies to be used to transmit the split sequence. This leads to greater frequency diversity and facilitates frequency and phase related signal measurements by a device receiving the signal.

Abstract: The use of multiple states of mobile communication device operation to allow a single base station to support a relatively large number of mobile nodes is described. The various states require different amounts of communications resources, e.g., bandwidth. Four supported states of operation are a on-state, a hold-state, a sleep-state, and an access-state. Each mobile node in the on-state is allocated communication resources to perform transmission power control signaling, transmission timing control signaling and to transmit data as part of a data uplink communications operation. Each mobile node in the hold-state is allocated communication resources to perform transmission timing control signaling and is provided a dedicated uplink for requesting a state transition and a shared resource for transmitting acknowledgements. In the sleep state a mobile node is allocated minimal resources and does not conduct power control signaling or timing control signaling. Data may be received in the on and hold states.

Abstract: Antennas and methods of manufacturing and using antennas suited for use in mobile devices are described. The described antennas include an antenna arm (104) and a conical spring radiating element (108) attached to one end of the arm. The spring radiating element (108) is covered by a protective cap (106) and can be compressed to fit inside the cap (106) for easy storage in a PC card. The antenna arm (104) may be implemented as a layered circuit board. In some embodiments the antenna arm (104) includes a radiating element, e.g., a conductive strip (1304), positioned along an edge of the arm (104) which will remain exposed even when the antenna is inserted into a PC card for storage. In various embodiments the spring radiating element (108) automatically extends when the antenna arm (104) is switched from a storage position to an active position, e.g., by pulling on the antenna arm to cause it to slide or swing out of a housing (102).

Abstract: This document describes a way to extend Mobile IP Authentication Authorization and Accounting (AAA) signaling to enable a node to request from a network operator combinations of home and local service capabilities (when roaming) in an efficient and scalable manner. It also enables the home and foreign service providers to constrain and account for actual services provided based on a combination of the foreign and home operator policy.

Abstract: An orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system using offsetting between cells, and in particular, the use of tone offsetting and time offsetting, is disclosed. More specifically, frequencies that define the tone set of one cell is offset from the frequencies that define the tone set of at least one adjacent cell. In other words, if a first base station is using tones F1, F2, . . . , FN within a frequency band, then a second base station adjacent to the first base station uses tones F1+&Dgr;f, F2+&Dgr;f . . . , FN+&Dgr;f within the same frequency band. Furthermore, the symbol timing of the base-station of one cell may be offset from the symbol timing of the base-station of an adjacent cell. Thus, if a first base station starts successive symbols at times T1, T2, and T3, then a second base station adjacent to the first base station starts its respective corresponding successive symbols at times T1+&Dgr;t, T2+&Dgr;t, and T3+&Dgr;t.

Abstract: Methods and apparatus for scheduling mobile stations (MSs) to download data and/or to control the rate of downloading to an MS from a base station (BS) as a function of downlink channel condition information are described. Artificial channel variations, which can be measured at the MS, and feedback to a BS for scheduling purposes, are introduced through the use of two or more transmitter antennas at a BS. Each of the antennas transmits a signal at the same frequency having the same information content, e.g., modulated data. However the signals are made to differ with time in their phase and/or amplitude to introduce what appear to be channel variations to the MSs.

Abstract: Methods and apparatus for decoding codewords using message passing decoding techniques which are particularly well suited for use with low density parity check (LDPC) codes and long codewords are described. The described methods allow decoding graph structures which are largely comprised of multiple identical copies of a much smaller graph. Copies of the smaller graph are subject to a controlled permutation operation to create the larger graph structure. The same controlled permutations are directly implemented to support message passing between the replicated copies of the small graph. Messages corresponding to individual copies of the graph are stored in a memory and accessed in sets, one from each copy of the graph, using a SIMD read or write instruction. The graph permutation operation may be implemented by simply reordering messages, e.g.

Abstract: Tone sequences in a frequency hopping arrangement are generated and assigned by advantageously employing a combination of a sequence generator and a sequence assignor to generate sequences and assign them on a time slot by time slot basis. In a transmitter, the sequence generator and sequence assignor, in combination with a user tone assignor are employed to generate and assign tone sequences to a user on a time slot by time slot basis. In a receiver, the sequence generator and sequence assignor, in combination with a user tone identifier are employed to generate sequences and to identify incoming tone sequences to a user on a time slot by time slot basis. Specifically, the sequence assignment in a time slot is such that a prescribed plurality of sequences is assigned to a particular user.

Abstract: Methods and apparatus for generating multi-tone signals, e.g., OFDM signals, are described. Analog signals corresponding to individual tones of a multi-tone signal are separately generated and filtered. Different prefixes are generated for each of the multiple tones. The prefixes for all the tones are of the same duration. One signal prefix is generated for each tone during each symbol transmission period. Each prefix may include multiple parts with a first part being generated from a current symbol and the second part being generated from the preceding symbol. By generating each multipart prefix from the periodic signal representing the current symbol and the periodic signal representing the preceding symbol, a smooth signal transition will occur at the point one symbol transmission period stops and the next one begins. Separate antennas are used to transmit signals corresponding to different tones of a multi-tone signal with the signals combining in the communications channel.

Abstract: In an orthogonal frequency division multiplexing (OFDM) based spread spectrum multiple access system the entire bandwidth is divided into orthogonal tones, and all of the orthogonal tones are reused in each cell. To reduce peak-to-average ratio at the mobile transmitter, each voice user is allocated preferably a single one, but no more than a very small number, of the orthogonal tones for use in communicating with the base station. Data users are similarly allocated tones for data communication, however, the number of tones assigned for each particular data user is a function of the data rate for that user. The tone assignment for a given user is not always the same within the available band, but instead the tones assigned to each user are hopped over time. More specifically, in the downlink, the tones assigned to each user are change relatively rapidly, e.g., from symbol to symbol, i.e., the user fast “hops” from one tone to another.

Abstract: OFDM signal communication methods and apparatus are described. In accordance with the invention OFDM signals are generated in the time domain with symbols being mapped to specific points in time. Training symbols may be included in the transmitted OFDM signal to facilitate symbol recovery. An exemplary receiver of the invention receives the OFDM signal from the communications channel, converts it into the frequency domain, and then filters it in the frequency domain to eliminate tones corresponding to other users. The filtered signal free of MAC interference is then converted into the time domain where channel estimation and compensation operations are performed. After channel compensation symbol recovery is performed in the time domain.