Chapter: Network Concepts and Standards
It employs the 1394 packet size and time stamp, so the proposed wireless scheme can seamlessly maintain 1394-based connectivity by wired or wireless means. Devices such as set-top are foreseen to convert MPEG-2 video to an IEEE 1394 data stream and send it over a W-OFDM radio system. The proposal by Philips and Wi-LAN is potentially capable of offering a 46-Mbit/second raw data rate over ranges exceeding 10 meters. A/V clusters installed in different rooms could connect wirelessly through walls.
Though the raw data rate of the Philips and Wi-LAN scheme is 46-Mbit/s , the net rate is 24 Mbits/s, after subtracting out the bit rates necessary for the W-OFDM headers and error correction (16 Mbits/s) and for the 1394 headers and error correction (6 Mbits). Theoretically OFDM can be used for outdoor wireless applications with severe multipath delay spread.
The IEEE 802.11 wireless Ethernet standard is designed for wireless transmission of data only; isochronous information is excluded. The approach uses the 2.4-GHz band and offers a raw data rate of up to 11 Mbits/s.
The Bluetooth scheme, meanwhile, targets short-distance links between cell phones and laptops with a 1-Mbit/s network that connects devices up to 10 meters apart. The frequency-hopping technology operates in the 2.54-GHz ISM band.
HomeRF also employs a frequency-hopping technology. It transmits data at 1.6 Mbit/s between home PCs and peripherals and supports up to four separate voice channels.