Nortel Networks Corporation

Apple Inc.

Anoop Nannra

Hasler Hayes

Martin Ridgway Handforth

Guy M Duxbury

Larry Marcanti

Brian Vezza

John Stankus

Martin Meier

Martin Jan Soukup

A system and method for preventing e-mail spoofing, in which a receiving e-mail checking server system sends a message to a confirmation server associated with a network domain of the sending system of a received e-mail message, to determine if the sender transmitted the message. The e-mail checking server sends a confirmation request e-mail, including a transmission time or unique message 'key' associated with the received e-mail, to the sending domain's confirmation server. When a confirmation request is received at the confirmation server, it replies with an indication whether the message was sent at the time indicated in the confirmation request, and/or whether the message key matches that of a previously transmitted message. The confirmation server checks whether the message was in fact sent based on stored values corresponding to the send time and/or message key stored for the confirmation request message. A message may further include indication that its origin can be confirmed. A receiver may maintain indications of domains capable of confirming sent e-mail messages, and determine a problem has occurred if no confirmations are received from a domain having that capability. An e-mail sender may mark domains from which it expects to receive e-mail confirmation requests, and determine a problem has occurred if e-mail messages sent to such domains fail to send confirmation requests.

System and method for confirming that the origin of an electronic mail message is valid

A system providing video data in which a constant bit rate data stream is provided between a video source and a video destination, and has a fixed data rate exceeding a predetermined minimum display rate associated with the video destination. Video data is conveyed from the video source to the video destination at the data rate, and is processed for display at the video destination at a varying display rate, between a minimum rate and a maximum rate. The minimum video data display rate at the video destination is less than the fixed data rate of the stream between the video source and the video destination, and excess received video data is stored in buffers in the video destination. Display of the received video data by a display device at the video destination is delayed from when the video data is received by a delay period, allowing buffers at the video destination to fill with video data. When display of the data is initiated, using the buffered video data, the video quality of the display can be improved, incorrectly received or missing frames can be retransmitted and received, and/or a fast forward function can be supported.

System and method for improving video quality using a constant bit rate data stream

A network element is configured to implement scheduled high-power Point-To-Point (PTP) and low-power Point-To-MultiPoint (TMP) transmissions. The high-power PTP and low-power PTMP transmissions may be scheduled as bursts on an 802.16 network to occur in both the downlink subframe and uplink subframe on a given frequency channel in the wireless network. The use of an air interface for both types of communications allows the PTP and PTMP communications to be scheduled relative to each other in a unified manner to increase quality of service and minimize interference between the backhaul PTP and access PTMP networks, even though the PTP and PTMP communications take place on the same channel using the same underlying wireless technology. Buffers may be used to store data received in a PTP downlink burst prior to transmission in a PTMP downlink burst, and may be used to store data received in an uplink PTMP burst prior to transmission in an uplink PTP burst.

Network element for implementing scheduled high-power PTP and low-power PTMP transmissions

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Ottawa, Canada

Anoop Nannra