Abstract:
A terminal is assigned an active identifier for use while in an active state of a connection with a base station. The base station periodically broadcasts the status of the active identifiers for that base station, e.g., via status validation bits that indicate whether each active identifier is currently assigned to a terminal or not assigned to any terminal. The base station may also broadcast the identity (e.g., a scrambling mask) of the terminal assigned with each active identifier that is currently in use. If a terminal believes that it is assigned a particular active identifier, then the terminal checks the status validation bit for this active identifier. If this status validation bit indicates that the active identifier is currently in use, then the terminal may further check the scrambling mask sent for the active identifier in order to determine whether the terminal is actually assigned the active identifier.
Abstract:
A method for reducing the peak-to-average ratio in an OFDM communication signal is provided. The method includes defining a constellation having a plurality of symbols, defining a symbol duration for the OFDM communication signal, and defining a plurality of time instants in the symbol duration. A plurality of tones are allocated to a particular communication device, and a discrete signal is constructed in the time domain by mapping symbols from the constellation to the time instants. A continuous signal is generated by applying an interpolation function to the discrete signal such that the continuous signal only includes sinusoids having frequencies which are equal to the allocated tones.
Abstract:
Techniques for efficiently sending reports in a wireless communication system are described. Reports may be sent repetitively in accordance with a reporting format. A terminal receives an assignment of a control channel used to send reports and determines a reporting format to use based on the assignment. The reporting format indicates a specific sequence of reports sent in specific locations of a control channel frame. The terminal generates a set of reports for each reporting interval and arranges the set of reports in accordance with the reporting format. The terminal repetitively sends a plurality of sets of reports in a plurality of reporting intervals. Reports may also be sent adaptively based on operating conditions. An appropriate reporting format may be selected based on the operating conditions of the terminal, which may be characterized by environment (e.g., mobility), capabilities, QoS, and/or other factors.
Abstract:
Allocation of a wireless communications system channel resource is managed by utilizing traffic segment allocation. This is realized by partitioning the channel resource into an assignment channel and a traffic channel in a fixed manner. The assignment channel includes assignment segments and the traffic channel includes traffic segments. The traffic segment is the basic traffic channel resource unit used to transport traffic data and has a prescribed finite time interval and bandwidth. Each traffic segment is associated with a so-called assignment segment in a prescribed manner. One or more traffic segments may be associated with a particular assignment segment. A base station broadcasts via an assignment segment which wireless terminal is to use a particular traffic segment. This is realized by transmitting a simply identifier for the particular wireless terminal assigned to the particular traffic segment in the assignment segment. Then, each active wireless terminal monitors all of the received assignment segments to detect any traffic channel assignments. Once a wireless terminal detects its identifier in an assignment segment, it proceeds to receive/transmit the traffic data in the traffic segment associated with the assignment segment including the detected identifier.
Abstract:
Improved timing synchronization and access control techniques for use in an orthogonal frequency division multiplexed (OFDM) wireless system or other type of wireless communication system. In accordance with the invention, an uplink synchronization and access control system is provided in which mobile stations transmit certain timing and access signals in dedicated intervals in an uplink stream. Access control is illustratively implemented as a two-stage process in which a given mobile first transmits a generic uplink access signal in one of the intervals. If this access is accepted, the base station transmits an access acknowledgment containing initial timing and power corrections, along with initial channel assignments on which the mobile can initiate a call set-up process. For re-synchronization, mobiles transmit timing synchronization signals in the dedicated timing and access intervals. The base station measures the arrival time of the signals, and sends back appropriate timing corrections. The invention thereby ensures that orthogonality between mobiles is maintained.
Abstract:
Latency in receiving and detecting paging messages at a wireless terminal is reduced by employing a unique “super” paging time slot format. A paging super time slot includes a plurality of prescribed time slots. Each wireless terminal is associated with cyclically recurring super time slots. A super slot is associated with one or more wireless terminals. A base station always selects the first available time slot in a super time slot to transmit a paging message to a wireless terminal that is associated with the super time slot. Each wireless terminal monitors every time slot in the associated super time slot until either detecting reception of its associated paging message or detecting an empty time slot. In another embodiment of the invention, a unique partially overlapping super time slot format is employed in which a super time slot has at least one time slot common to its adjacent super time slots. This allows wireless terminals associated with adjacent super time slots to share the common at least one time slot. In turn, this results in balanced traffic loads, smoothed traffic fluctuation and reduced congestion.
Abstract:
A base station uses a common link layer controller for multiple physical attachment points to facilitate concurrent wireless connections between different sector physical attachment points and a wireless terminal using the same link layer link. A wireless terminal maintains multiple simultaneous wireless connections for the same link layer link. A packet of user data is fragmented into a plurality of grouping of MAC frames, thus a packet portion can be communicated over a connection. A single packet is sometimes communicated with different portions conveyed over different wireless connections. Automatic repeat request, using the common link layer controller, allows for retransmission of a packet portion over a different connection than it was initially transmitted over. A wireless terminal sends connection request messages including lists of link layer identifiers associated with the wireless terminal. A base station responds with an indication of whether logical link state was already present.
Abstract:
Methods and apparatus related to assignment in a wireless communications system are described. A mobile is assigned an identifier and a mask value, e.g., as part of a state transition message. The mobile uses the assigned identifier and/or the assigned mask value in determining whether assignments included in assignment messages, e.g., traffic channel assignment messages, are directed to the wireless terminal. Predetermined associations between assignment slots, assigned segments, and/or mask values are utilized to limit control signaling overhead. Different groups of segments are available for assignment to different wireless terminals as a function of mask values. Different types of assignment messages use different amounts of information bits to convey the assignment. Some types of assignments use a wireless terminal identifier, while other types of assignments use a wireless terminal identifier and a mask identifier. The mask identifier, e.g., a single bit, allows for selection between a subset of the potential masks used in the system.
Abstract:
A method for reducing the peak-to-average ratio in an OFDM communication signal is provided. The method includes defining a constellation having a plurality of symbols, defining a symbol duration for the OFDM communication signal, and defining a plurality of time instants in the symbol duration. A plurality of tones are allocated to a particular communication device, and a discrete signal is constructed in the time domain by mapping symbols from the constellation to the time instants. A continuous signal is generated by applying an interpolation function to the discrete signal such that the continuous signal only includes sinusoids having frequencies which are equal to the allocated tones.
Abstract:
A method for reducing the peak-to-average ratio in an OFDM communication signal is provided. The method includes defining a constellation having a plurality of symbols, defining a symbol duration for the OFDM communication signal, and defining a plurality of time instants in the symbol duration. A plurality of tones are allocated to a particular communication device, and a discrete signal is constructed in the time domain by mapping symbols from the constellation to the time instants. A continuous signal is generated by applying an interpolation function to the discrete signal such that the continuous signal only includes sinusoids having frequencies which are equal to the allocated tones.