System and method for synchronization of isochronous data streams over a wireless communication link
A transmitter ( 500 ) is provided for transmitting host data over a wireless channel. The transmitter ( 500 ) includes a free-running timer ( 560 ) that provides a series of increasing free-running timing values; a host interface circuit ( 510 ) that receives host data from a local host circuit and a first free-running timing value from the series of increasing free-running timing values; a detection circuit ( 530 ) for detecting a global synchronizing event and receiving a second free-running timing value from the series of increasing free-running timing values, and for placing the host data and the first free-running timing value into a host interface packet; and a wireless transceiver ( 530 ) for adding the second free-running timing value and an identifier for the global synchronizing event to the host interface packet to form an air link frame, and transmitting the air link frame over a wireless channel to a remote wireless device.
1 . A method of time stamping data in a local wireless device, comprising:
sequentially detecting a plurality of global synchronizing events;
receiving host data from a local host circuit;
forming the host data into data packets, each of the data packets including time stamp information, the time stamp information indicating when a selected one of the data packets should be processed by a remote receiver relative to other of the data packets; and
transmitting the data packets over a wireless channel to a remote wireless device,
wherein the time stamp information is identified relative to one of the plurality of global synchronizing events.
2 . A method of time stamping data in a local wireless device, as recited in claim 1 , wherein the global synchronizing events are one of: a plurality of network beacons sent over a wireless channel by a network coordinator, a plurality of network beacons generated by the local wireless device, a plurality of global positioning system signals sent over a wireless channel, a plurality of synchronization packets sent over a wireless channel by a remote network device, a plurality of synchronization packets generated by the local wireless device, and a plurality of synchronization signals sent over a wired channel.
3 . A method of time stamping data in a local wireless device, as recited in claim 1 , wherein the data packets include two or more levels of encapsulation.
4 . A method of time stamping data in a local wireless device, as recited in claim 3 , wherein the time stamp information includes first and second time stamp markers, the first time stamp marker being in a first of the two or more levels of encapsulation, and the second time stamp marker being in a second of the two or more levels of encapsulation.
5 . A method of time stamping data in a local wireless device, as recited in claim 4 ,
wherein the first time stamp marker comprises a first free-running timer value corresponding to the host data, and
wherein the second time stamp marker comprises a global synchronizing event identifier and a second free-running timer value corresponding to the global synchronizing event.
6 . A method of time stamping data in a local wireless device, as recited in claim 1 , wherein the time stamp information comprises a global synchronizing event identifier and an offset timing value relating the host data in time with respect to the global synchronizing event.
7 . A method of time stamping data in a local wireless device, as recited in claim 1 , wherein the method is embodied in an integrated circuit.
8 . A method of time stamping data in a local wireless device, as recited in claim 1 , wherein the method is embodied in an ultrawide bandwidth transceiver.
9 . A method of time stamping data in a local wireless device, as recited in claim 1 , wherein the host data comprises one of: MPEG cells, encapsulated MPEG cells, Ethernet packets, internet protocol packets, and PCM audio samples.
10 . A method of coordinating data in a wireless receiver, comprising:
sequentially detecting a plurality of global synchronizing events;
receiving a data packet from a remote device over a wireless channel;
extracting time stamp information from the data packet, the time stamp information indicating when the received data packet should be processed by the wireless receiver relative to other data packets;
extracting host data from the data packet; and
passing the host data to a local host in response to the time stamp information,
wherein the time stamp information is identified relative to one of the plurality of global synchronizing events.
11 . A method of coordinating data in a wireless receiver, as recited in claim 10 , wherein the global synchronizing events are one of: a plurality of network beacons sent over a wireless channel by a network coordinator, a plurality of network beacons generated by the local wireless device, a plurality of global positioning system signals sent over a wireless channel, a plurality of synchronization packets sent over a wireless channel by a remote network device, a plurality of synchronization packets generated by the local wireless device, and a plurality of synchronization signals sent over a wired channel.
12 . A method of coordinating data in a wireless receiver, as recited in claim 10 , wherein the data packets include two or more levels of encapsulation.
13 . A method of coordinating data in a wireless receiver, as recited in claim 12 , wherein the time stamp information includes first and second time stamp markers, the first time stamp marker being in a first of the two or more levels of encapsulation, and the second time stamp marker being in a second of the two or more levels of encapsulation.
14 . A method of coordinating data in a wireless receiver, as recited in claim 13 ,
wherein the first time stamp marker comprises a first free-running timer value corresponding to the host data, and
wherein the second time stamp marker comprises a global synchronizing event identifier and a second free-running timer value corresponding to the global synchronizing event.
15 . A method of coordinating data in a wireless receiver, as recited in claim 10 , wherein the time stamp information comprises a global synchronizing event identifier and an offset timing value relating the host data in time with respect to the global synchronizing event.
16 . A method of coordinating data in a wireless receiver, as recited in claim 10 , wherein the method is embodied in an integrated circuit.
17 . A method of coordinating data in a wireless receiver, as recited in claim 10 , wherein the method is embodied in an ultrawide bandwidth transceiver.
18 . A method of coordinating data in a wireless receiver, as recited in claim 10 , wherein the host data comprises one of: MPEG cells, encapsulated MPEG cells, Ethernet packets, internet protocol packets, and PCM audio samples.
19 . A device for transmitting host data, comprising:
a free-running timer for providing a series of increasing free-running timing values;
a host interface circuit for receiving host data from a local host circuit and a first free-running timing value from the series of increasing free-running timing values, and for placing the host data and the first free-running timing value into a host interface packet;
a detection circuit for detecting a global synchronizing event and receiving a second free-running timing value from the series of increasing free-running timing values; and
a wireless transceiver for adding the second free-running timing value and an identifier for the global synchronizing event to the host interface packet to form an air link frame, and transmitting the air link frame over a wireless channel to a remote wireless device.
20 . A device for transmitting host data, as recited in claim 19 , further comprising a first-in-first-out buffer located between the host interface circuit and the wireless transceiver for passing the host interface packet.
21 . A device for transmitting host data, as recited in claim 19 , wherein the global synchronizing event is one of: a network beacon sent over a wireless channel by a network coordinator, a network beacon generated by the wireless transceiver, a global positioning system signal sent over a wireless channel, a synchronization packet sent over a wireless channel by a remote network device, a synchronization packet generated by the wireless transceiver, and a synchronization signal sent over a wired channel.
22 . A receiver device for receiving host data over a wireless channel, comprising:
a free-running timer for providing a series of increasing free-running timing values;
a detection circuit for detecting a global synchronizing event and receiving a free-running timing value from the series of increasing free-running timing values; and
a wireless transceiver for receiving an air link frame having a host interface packet and a first time stamp, the host interface packet including a second time stamp.
a first time stamp processor for receiving the first time stamp and comparing the first time stamp with a recorded free-running timing value to determine a timer correction value for the receiver device;
a second time stamp processor for receiving the second time stamp and generating a host data process signal based on the second time stamp, the correction value, and a latency value, the latency value indicating an expected maximum latency time for the air link frame over the wireless channel; and
a host interface circuit for receiving and processing the host interface frame based on the host data process signal, and providing the host data to a local host circuit.
23 . A receiver device for receiving host data over a wireless channel, as recited in claim 22 , further comprising a first-in-first-out buffer located between the wireless transceiver and the host interface circuit for passing the host interface packet.
24 . A receiver device for receiving host data over a wireless channel, as recited in claim 22 , wherein the global synchronizing event is one of: a network beacon sent over a wireless channel by a network coordinator, a network beacon generated by the wireless transceiver, a global positioning system signal sent over a wireless channel, a synchronization packet sent over a wireless channel by a remote network device, a synchronization packet generated by the wireless transceiver, and a synchronization signal sent over a wired channel.