Good Comms is essential for the Army to perform effective operations at home and abroad. This was highlighted during the Kosovo Campaign when Serbian jamming completely negated the radio links between British Land, Air and Sea Forces. Thus, the Nokia came into its own and the Ministry of Defence quickly negotiated with Vodafone, Orange and others for free calls to keep the links up.
There are dozens of different comms methods in service today - the Clansman family making up most of it (although on a small scale - see above) - amply provided by Signals Regiments across the world.
BOWMAN has largely replaced most Comms assets in service but it still has teething problems - definitely not squaddy proof.
When Comms are lost for any reason the fabled Sporadic E receives its Hourly/ Daily/Weekly/Monthly* excuse outing.
(*Delete as applicable)