Research in Motion Corporation

Blackberry Corporation

Haiyang Yin

Alexander Shatsky

Valentina Iqorevna Kramarenko

Richard John George

Lap Luu

Third party call control in a service management platform (SMP) of an enterprise system comprising a private branch exchange (PBX) in communication with the SMP over a trunk and line. Receiving a request over the line for communication involving a device. Invoking reliable transmission of provisional responses in the trunk. Receiving a receive only session description over the trunk. Invoking specific event notification between the SMP and PBX for calls answered between the device and PBX. Receiving notification of a call answered between the device and PBX. Responding to the request with the first session description as a send/receive offer. Receiving acknowledgement including a second send/receive answer session description over the line. Updating the trunk the second description as a send/receive update. Receiving a third session description with a successful response message from the PBX; the third session description being a send and receive copy of the first session description.

Expedited media interconnection in third party call control

An apparatus and method are described for resolving a glare condition between two SIP endpoints. The method allows a third party call control controller to resolve the glare condition when the ownership status of each dialog is the same, by initiating a back-off period of time at the apparatus based on the ownership status of the SIP dialog and re-sending a re-INVITE message to the end point after expiry of the back-off period of time.

Apparatus and method for resolving a race condition between two session initiation protocol (SIP) end points

Control and status information between a mobile device and another device can be signaled over a voice channel using DTMF tones, e.g., a pre-defined sequence of DTMF tones can signal a desired message (more generally, a feature code). Tones sent are separated from each other by a time gap (Ttimer). If a receiving device does not receive a sequence of DTMF tones that can be matched to stored definitions of feature codes, then the receiving device generates a negative ACK. Also, if the sending device does not receive either negative or positive ACK, then sending device resends all tones of the feature code after a retry delay (Ttimer). Rather than having the Ttimer start when tones for a feature code start to be transmitted, the Ttimer is started after the Ttimer expires for the last tone of a feature code. Thus, only one timer is running (either Tor T), rather than having multiple timers running concurrently. Race conditions between the timers are avoided.

Systems and methods of timing DTMF tones for telephony control

A system and method for handling stale messages is presented. A first message is transmitted to a peer entity. The first message includes a first timestamp. A second message is received from the peer entity. The second message is related to the first message and includes a second timestamp. A third message is received from the peer entity. The third message includes a third timestamp. A staleness of the third message is determined using the first timestamp, second timestamp, and third timestamp. When the third message is stale, the third message is at least one of ignored and discarded. When the third message is not stale, the third message may be processed.

Growing community of inventors

Waterloo, Canada

Haiyang Yin