Motorola Corporation

Robert D LoGalbo

Alan P Conrad

Darrell James Stogner

Bradley Michael Hiben

Donald G Newberg

Shmuel Silverman

Randy L Ekl

Tyrone D Bekiares

Gregory A Dertz

Mark Conrad Cudak

Apoorv Chaudhri

Ron Rotstein

Kevin G Doberstein

Scott Michael Alazraki

George Popovich

John B Preston

Charles J Malek

Chet A Lampert

Jeffrey S Anderson

Stan Jelavic

A method and system for wireless data transmission between at least three stations use multiple frequency bands for simultaneous channel communications. The method includes transmitting a Request To Send (RTS) packet from a first station to an intermediate second station over a first frequency band. Two Clear To Send (CTS) packets, which CTS packets include transmission timing information, are then transmitted from the second station simultaneously both to the first station and to a third station. The CTS packet sent to the first station is transmitted over the first frequency band and the CTS packet sent to the third station is transmitted over a second frequency band. A data packet from the first station is then transmitted to the second station. The third station suspends, based on the transmission timing information included in the CTS packets, any unicast transmission to the second station during the transmission of the data packet from the first station to the second station.

Medium access control for simultaneous channel communications

The present invention allows a single access point ('AP';) to support a plurality of devices () operating on different frequency bands. During a first period of time, the AP initiates a contention free period at a first frequency. The AP switches from the first frequency to a second frequency, and communicates with devices operating at the second frequency. Periodically during the first period of time, the AP temporarily ceases communication with devices operating at the second frequency to initiate a contention free period at the second frequency, switch from the second frequency to the first frequency, initiate another contention free period at the first frequency, and switch from the first frequency back to the second frequency.

Method for supporting a plurality of subscribers operating on different frequency bands using a single access point

In an outbound transmission (), an address of a first subscriber unit assigned to transmit in a first inbound slot is identified. With one bit in the outbound transmission (), an additional inbound slot the first subscriber unit is assigned to transmit is identified.

Method for assigning inbound transmissions with minimal signaling overhead

Disclosed are methods for adjustment values. In one embodiment, a cumulative adjustment value is provided in memory, an inbound signal is transmitted to a base station during a random access opportunity, and a relative adjustment value is received from the base station. Then, the relative adjustment value is summed with the cumulative adjustment value to create a new cumulative adjustment value which is stored in the memory. Finally, a subsequent inbound signal is transmitted using the new cumulative adjustment value during a reserved access opportunity.

Relative adjustment value for inbound time-slotted transmissions

Methods for sequencing datagram transmissions are disclosed, including, receiving an unqueued segment to be enqueued in a queue. The queue comprises at least one segment. Determining a priority level and a number of attempted transmissions for the unqueued segment (). If the unqueued segment is enqueued in front of a segment belonging to a datagram in the queue, and at least one segment belonging to the datagram has been transmitted before all the segments belonging to the datagram have been transmitted, at least one of the following functions is performed: discarding any remaining segments belonging to the datagram in the queue, transmitting any remaining segments belonging to the datagram in the queue, and re-enqueuing segments belonging to the datagram at the same location in the queue as the partially transmitted datagram, but with a different identifier.

Methods for sequencing datagram transmissions

Encryption synchronization (e-sync) is maintained between a transmitter () and one or more receivers () in a multi-modulation TDM system () where information is communicated in slots () comprising a slot header () and one or more data blocks (), and wherein the data blocks are eligible to be encoded at different modulation rates thereby creating a likelihood of different numbers of blocks in different slots. The receiver and transmitter employ respective encryption elements () comprising e-sync shifter elements () and encryption algorithm blocks (). The e-sync shifter element provides an e-sync signal defining an encryption state vector to the encryption algorithm block and is operable to advance the encryption state vector (in the case of the receiver) according to a number of received bits plus a variable number of bits. The variable number depends on the number of bits within a block, the maximum number of blocks that could be within a slot and the actual number of blocks within the slot.

Method and apparatus to maintain encryption synchronization in a multi-modulation TDM system

Disclosed is a method for performing handoff in a communication system of access points and a mobile station, where the mobile station is associated with a first access point. The first access point receives a first transmission at a first signal quality from the mobile station and receives a second transmission that indicates a second signal quality at which a second access point is receiving transmissions from the mobile station. The first access point compares the first signal quality with the second signal quality and when the second signal quality is greater than the first signal quality, the first access point signals the second access point to initiate a handoff with the mobile station. The second access point responds by sending a disassociation message to the mobile station to disassociate with the first access point, wherein the disassociation message is addressed as if it originated from the first access point.

Method for performing a seamless handoff in a communication system

A radio frequency communications system () includes wireless terminals () and base sites (). The wireless terminals communicate with the base sites over a radio frequency channel (). The base sites are interconnected to each other and other network elements via a packet network. The communication system has a radio frequency channel () with time slots () for transmission of both delay-sensitive data, such as streaming audio and video, and non-delay-sensitive data. A method and apparatus are provided for determining whether a time slot in the radio frequency channel is to be allocated to delay-sensitive data or non-delay-sensitive data (). Each packet of data transmitted over the wireless channel has a type of service field (). The type of service field has a precedence or priority value () and a service type (). The priority values are used to determine which packet should be transmitted across the radio frequency channel next and the service type determines the transmission protocol.

Method and apparatus for organizing and scheduling multimedia data transfers over a wireless channel

A slot format and acknowledgment method for use in a communication network that contains one or more wireless links. The slot format provides for the segmenting and reassembly of packets for transport over a wireless link. It also provides support for multiple types of service for the data being carried over the wireless link as well as allocating of access to the wireless link among a plurality of communication units. The acknowledgment method provides for detection of errors over the wireless link, the selective acknowledgment of error-free transmissions and the selective resending of transmissions received in error.

Slot format and acknowledgement method for a wireless communication system

In a system having at least a first slot () and a first header (), at least one field is provided in the first header (). The first slot () is configured into at least a first segment and a second segment or into at least a signaling communications path comprising a plurality of messages, based on a value associated with at least a portion of the at last one field associated with the first header. The first segment/message is address to a first subscriber unit and the second segment/message is addressed to a second subscriber unit.

Methods of addressing and signaling a plurality of subscriber units in a single slot

An outbound message () identifies a slot type associated with each timeslot in a scheduling period. In one embodiment, the outbound message further identifies at least an address of a first subscriber group assigned to transmit in a first timeslot () if the slot type of the first timeslot is of a first type and an address of a second subscriber group assigned to transmit in a second timeslot () if the slot type of the second timeslot is of a second type, wherein the first type and the second type could be the same or different. In a second embodiment, the outbound message further identifies at least a group address associated with a plurality of subscriber units assigned to transmit in a first timeslot if the slot type of the first timeslot is of a first type. In yet a third embodiment, the outbound message further identifies an address of a first subscriber group assigned to transmit in a first timeslot if the slot type of the first timeslot is of the first type, and a second timeslot () of a second type.

Method for allocating channel resources in a distributed control channel system

A scalable slot format defining positions of synchronization symbols, pilot symbols and data symbols for various numbers of sub-channels and various lengths of time in a multi-carrier communication system. An initial pattern ( ) and one or more follow-on patterns ( ) are defined identifying positions of data symbols, synchronization symbols and pilot symbols for a first number of sub-channels corresponding to a first bandwidth. An extended pattern is constructed from the one or more follow-on patterns. The extension pattern is appended to the initial pattern to form a base pattern ( ). The base pattern ( ) is replicated zero or more times to form an expanded pattern ( ) identifying positions of data symbols, synchronization symbols and pilot symbols for an expanded number of sub-channels corresponding to a second bandwidth. The slot format may be implemented by a transmitter ( ) having subdivided an original information signal into M bit streams and having encoded each of the M bit streams to 16QAM symbols to form M symbol streams, by inserting synchronization and pilot symbols into each of the M symbol streams at positions determined by the expanded pattern.

Time and bandwidth scalable slot for mobile data system

A transceiver device having a forward error correction decoder providing at least one forward error correction metric and a data integrity monitor providing at least one automatic retry query metric to a data processor or CPU. The data processor or CPU is responsive to the forward error correction metric and the automatic retry query metric and has outputs providing a forward error correction value and an automatic retry query value to the forward error correction/data encoder and decoder.

Dynamically changing forward error correction and automatic request for

An improved synchronization method and apparatus, according to the invention, is provided. According to the invention, in a simulcast system having a remote site receiving frames from a base site, each frame containing a predetermined number (k) of transmit sample periods, and the transmit sample clock and remote synchronization clock frequencies known (f.sub.tx and f.sub.pps respectively), the remote site synchronizes a frame as follows. First, it receives a frame from the base site. Second, it determines the sequence number n for the frame. Third, it determines the launch time the first frame was to be broadcast from the remote site. Fourth, it computes a realignment time based on [(n-1)*(k)+launch time for first frame] MOD (f.sub.tx f.sub.pps). Fifth, it transmits the first bit of the frame at the realignment time.

Growing community of inventors

Hoffman Estates, IL, United States of America

Robert D LoGalbo