We tested the PL-200AV Push by connecting a pair of units to provide internet access from a router in the study to a PC in the living room of a self-contained cottage built onto the end of the house. A direct route would send the signal through a total of 7 rooms including the study and the living room, over a distance of 23m (75ft), although following the electrical wiring system the signal path may be longer. The signal path also goes through a total of two RCD fuseboxes to exit the house and enter the cottage. DECT cordless phones and WiFi have been tried over this route, but no signal was received in the living room. On plugging in the two Homeplug units, the powerline activity LED illuminated amber, indicating a connection rate of between 40 and 105 Mbps. The full ADSL speed from the router (around 5 Mbps here) was instantly available, and latency across the connection was in the region of 2ms, which should please gamers. An ftp file transfer across the connection went at an average speed of 25Mbps, not bad for a situation where WiFi doesn’t work at all. The connection has been in use for several days now and has been completely stable and reliable. The PL-200AV Push is available from Amazon UK.

The Licence-Exemption Framework Review extends the SFR by examining a number of specific issues concerning the management of spectrum used by licence-exempt devices, including;

• Should spectrum be reserved for exclusive licence-exempt use by a single wireless application (i.e. application-specific spectrum)? Or should multiple applications be allowed to share the spectrum (i.e. spectrum commons)?
• Is there a frequency limit above which all spectrum use can be made exempt from licensing? If so, what is the value of this limit?
• Is there a transmission power limit below which all emissions can be made exempt from licensing? If so, what is the value of this limit and how should it vary as a function of frequency?

Ofcom is known to believe that, in general, application-specific allocations for licence-exempt devices result in inefficient utilisation and fragmentation of spectrum, and instead prefers the ‘spectrum commons’ model which is believes would maximise the value derived from any spectrum set aside for licence-exempt use. However, they do not propose the retrospective application of the spectrum commons model to existing licence-exempt authorisations, as this may result in harmful interference to legacy technologies.

The review also proposes more licence-exempt spectrum above 40 GHz, and more licence-exempt low power spectral density use, similar to ultra-wideband, on a non-interference non-protected basis.