Trading Update

SOFTWARE RADIO TECHNOLOGY PLC                         

                           ("SRT" or the "Company")                            

                                TRADING UPDATE                                 

Software Radio Technology, the AIM-quoted developer and licensor of digital
wireless technology reference designs, which facilitate and fast-track the
manufacture of sophisticated digital communications and tracking/surveillance
products within the professional homeland security market, is pleased to
provide a trading update following its financial year end, the first since the
Company's admission to AIM in November 2005.

The preliminary results announcement for the year ended 31 March 2006 will be
made in the week commencing 12 June 2006. The Directors anticipate that the
trading results, before an exceptional item described below, will be slightly
ahead of market expectations published prior to the Company's admission to AIM.

Highlights:

TETRA (Professional mobile radio)

  * SRT currently has TETRA handset development contracts with five customers,
    of which three are in China and one each in South Korea and Taiwan. All of
    the customers are planning volume production of handsets, thereby
    generating royalties for SRT, during the Company's current financial year
    ending 31 March 2007.
   
  * A key recent development was the award of a contract for the supply of
    TETRA handsets by a major agency of the Chinese Government to Tianjin
    Communication & Broadcasting Group ("TCB"), one of SRT's customers.
   
  * TCB has already placed an order with SRT for a small quantity of ASIC chips
    to enable a pre-production run of TETRA handsets. The Directors anticipate
    that TCB will commence volume production within the next six months.
   
  * Shenzhen HYT Science & Technology Co. Ltd, another TETRA customer, has also
    placed an order of ASIC chips for pre-production manufacturing.
   
  * The Company's contract with Hisense Co. Ltd has not progressed as quickly
    as anticipated. SRT has agreed to devote further resources to support the
    customer, thereby minimising the delay and ensuring the customer enters
    full production by the end of the year.
   
AIS (Automatic Identification Systems)

  * The Company formally launched its low cost AIS Class B transponder design
    at the London Boat Show in January 2006.
   
  * In January SRT signed its first AIS Class B contract and is in active
    negotiations with companies worldwide.
   
  * The response to the launch from potential customers around the world has
    been extremely encouraging. This has clearly demonstrated the demand,
    fuelled primarily by concerns over homeland security, for an AIS system
    which is priced at a level appropriate for the smaller commercial and
    leisure vessel markets.
   
  * The Directors believe that AIS Class B represents a fast developing,
    potentially mass market, in which SRT holds a major competitive advantage
    with its low cost product available for sale or licensing.
   
Exceptional item

An exceptional, non-cash accounting charge to the profit and loss account in
the year ended 31 March 2006 of approximately £600,000 is expected to arise as
a result of the implementation of UITF 17 in respect of the grant of share
options at the time of admission to AIM.

                                    -ends-                                     

Software Radio Technology plc                                    01761 409500
                                                                             
Shamus Kelly                                     [e-mail]
                                                                             
Westhouse Securities LLP                                        0161 838 9140
                                                                             
Tim Feather                               [e-mail]
                                                                             
Tavistock Communications                                        020 7920 3166
                                                                             
Christian Taylor-Wilkinson                  [e-mail]

Notes for Editors

About Software Radio Technology

SRT is a developer and licensor of digital wireless technology reference
designs which facilitate and fast-track the manufacture of sophisticated
digital communications and tracking/surveillance products for use within the
professional homeland security market.

SRT currently licenses technology solutions for TETRA handsets (communication
devices used by professional users such as police & military) and automatic
identification systems (AIS) for ships and boats.