P1905. This permits a device to use wired ethernet, powerline or wireless communication as available to provide a redundant and reliable failover thought to be particularly important in consumer applications where there is no onsite expertise typically available to debug connections. Versions HomePlug 1.0 The first HomePlug specification, HomePlug 1.0, provides a peak PHY-rate of 14 Mbit/s. It was first introduced in June, 2001 and has since been replaced by HomePlug AV. On May 28, 2008 Telecommunications Industry Association (TIA) incorporated HomePlug 1.0 powerline technology into the newly published TIA-1113 international standard. TIA-1113 defines modem operations on user-premises electrical wiring. The new standard is the world's first multi-megabit powerline communications standard approved by an American National Standards Institute (ANSI)-accredited organization. The HomePlug 1.0 MAC Layer uses channel access based on Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) to transport data from 46 to 1500 bytes long from encapsulated IEEE 802.3 frames as MAC Service Data Units (MSDUs) (so doesn't support jumbo frames). HomePlug 1.0 Turbo adapters comply with the HomePlug 1.0 specification but employ a faster, proprietary mode that increases the peak PHY-rate to 85 Mbit/s. HomePlug 1.0 Turbo modems were only available from Intellon Corporation. HomePlug AV The HomePlug AV specification, which was introduced in August 2005, provides sufficient bandwidth for applications such as HDTV and VoIP. HomePlug AV offers a peak data rate of 200 Mbit/s at the physical layer, and about 80 Mbit/s at the MAC layer. HomePlug AV devices are required to coexist, and optionally to interoperate, with HomePlug 1.0 devices. The physical layer uses OFDM carriers spaced at 24.414 kHz, with carriers from 2 to 30 MHz. Depending on the signal to noise ratio, the system automatically selects from BPSK, QPSK, 16 QAM, 64 QAM, 256 QAM, and 1024 QAM, on a carrier by carrier basis. Utilizing adaptive modulation on up to 1155 OFDM sub-carriers, turbo convolution codes for error correction, two-level MAC framing with ARQ, and other techniques, HomePlug AV can achieve near the theoretical maximum bandwidth across a given transmission path. For security reasons, the specification includes key distribution techniques and the use of 128 bit AES encryption. Furthermore, the specification's adaptive techniques present inherent obstacles to eavesdropping and cyber attacks. Some Qualcomm Atheros-based adapters comply with the HomePlug AV specification but employ a proprietary extension that increases the PHY-rate to 500 Mbit/s primarily by using a wider spectrum. HomePlug AV2 The