1143 results about "Acknowledgement" patented technology

The disclosed invention is referred to a method for optimising the random access procedures in third generation CDMA cellular telephony systems. The particular embodiment of the example concerns a TD-SCDMA-TDD synchronous realization. The disclosed procedure includes a preliminary part charged to the network (BSSC, MSC) only for establishing the following associations between the configuration parameters of the involved physical channels: one signature burst (SYNC1) is associated to one forward access channel (P-FACH) only, in order to avoid any, ambiguity in the mobile stations about where to look for the expected acknowledgement from the network; one random access common channel (P-RACH) is associated to one forward access channel (P-FACH) only, in order to reduce collision on the latter (P-RACH); one access grant channel (P / S-CCPCH, AGCH) only is associated to one random access common channel (P-RACH), in order to avoid any ambiguity in the mobile stations about where to look for the expected answer from the network with the indication of the dedicated service channels (DPCH); and each complete associative link binding the involved physical channels is included in the system information and broadcasted into the serving cell to be read by the mobile stations (MS, UE) when entering an actual part of the procedure charged to exchange protocol messages with the network (BSSC, MSC) through said associative links that being signalling at once to the mobile stations the route towards the services offered by the network, simplifying the access procedure consequently. Suitable groupings among: Downlink pilot sequences, Uplink pilot sequences, scrambling codes, basic midambles, are carried out in a cell-discriminating way and broadcasted into the cell to simplify the serving cell selection procedure (<cross-reference target="DRAWINGS">FIG. 1< / cross-reference>).

Upon receiving an acknowledgement after retransmission of a data segment, an acknowledgement number contained in the acknowledgement is compared with an acknowledgment number expected to be contained in an acknowledgement pertaining to the retransmitted data segment. When the former is larger than the latter, it is determined that the acknowledgement pertains to a data segment that was originally transmitted.

One or more flow control modules, implemented on various types of network topologies, provide a number of functionalities for controlling the flow of IP packets (such as TCP / IP packets) over a network connection. The flow control modules may be implemented within a sender and / or receiver or may be deployed into a network as a separate device without requiring significant additional resources.

A protocol for acknowledging receipt of a multicast or broadcast frame by a wireless unit is described. One embodiment, an Eavesdrop Unicast frame is created for use in a wireless network operated in accordance with IEEE 802.11. The Eavesdrop Unicast frame allows the targeted wireless unit to transmit acknowledgement (ACK) frame but is configured so that other wireless units can scan and obtain information therefrom. Another embodiment is similar in configuration to the Eavesdrop Unicast frame but is fully compliant with IEEE 802.11. Therein, a multicast or broadcast frame is transmitted but one wireless unit is configured to acknowledge receipt of the multicast or broadcast frame. The acknowledgement is accomplished through transmission of a data frame. Yet another embodiment is the transmission of broadcast or multicast frames into corresponding unicast frames.

A system and method for enabling a first device (502, 504, 506) that may optionally roam between at least first and second wireless networks (500, 1102) to communicate with a second device (502, 504, 506) that may optionally roam between the at least first and second wireless networks (500, 1102). The devices (502, 504, 506) are preferably registered to each network in which the device may roam. A routing switch (1112) first transmits a data message to the receiving device at the last known location of the receiving device. If a negative acknowledgement is received, the message is routed to all other networks to which the receiving device is registered, either serially or in parallel, depending upon the configuration of the transmitting network. Routing devices (1112) and / or gateways (1110) are preferably provided for each network (500, 1102) to provide any required protocol and / or message format conversions.

A sending device prepares a key for each electronic message sent by the device by applying an algorithm to specified data in the message and then incorporates the key in the message. A receiving device, upon receipt of an electronic message, locates the incorporated key and the data from which a sending device practicing the invention would have prepared it. The receiving device communicates a confirmation request to the purported sending device which contains the key and the data for its preparation. The sending device receives the confirmation messages and prepares a comparison key by applying the algorithm to the data in the confirmation request. The sending device replies to the confirmation request confirming that the sending device sent the message if the comparison key matches the key in the confirmation request and otherwise responds with a denial.