Brilliant little networked Digitally Enhanced Cordless Telephone system by Yealink, can be used as a stand-alone phone system
One base and up to eight handsets with the ability to add range via extender / repeater units. Centrally locate the W60P base then add repeaters connected wirelessly to the base (a repeater cannot connect to a repeater, see the W80DM for this). The W60B repeaters plug into the mains then connect to the base unit which requires either mains and a CAT5/6 connection to the Internet or a PoE CAT5/6 connection.
Each handset may have its own extension number and even its own dedicated external telephone number as well as being part of a ring group making this the ideal solution for a business of eight or less users covering something like a small Nursing Home or offices where you need to move about, office to warehouse etc.