Spirent Solutions Accelerate Deployment of Commercial Location Based Services; User-Plane Capability Addresses New LBS Technology.

NEW ORLEANS -- Spirent Communications(TM), a wholly owned business group of Spirent plc (NYSE:SPM) (LSE:SPT), announces an important advance in ensuring successful next-generation location-based services (LBS) deployment over the world's wireless networks. Spirent's PLTS Position Location Test System is now shipping with the ability to evaluate the latest technologies chosen by world leading CDMA network operators for commercial LBS deployment. With its ULTS UMTS Location Test System offering an equivalent solution for GSM and WCDMA, Spirent has again extended its global leadership in characterizing the performance and end-user experience of LBS applications.

Network operators around the world are continuously seeking the next 'killer app' and commercial LBS are increasingly seen as a key differentiator. Potential applications include 'friend finder', point of interest services, location-aware gaming, and workforce management. Due to the high level of content necessary to make these applications valuable, services are being deployed using an IP-based approach known as 'user plane', in which location-sensitive data is transferred between the mobile device and network via packet data.

Spirent's PLTS now offers an integrated 'user plane' network emulation option. This new capability enables leading technology suppliers, CDMA mobile device manufacturers and network operators to address reliability and accuracy issues that can negatively impact the end-user experience. By testing in a controlled and repeatable lab-based environment, PLTS can substantially reduce the need for expensive and time-consuming field trials. The system played a key role in enabling CDMA network operators to meet the FCC's E911 Phase II mandate in the United States. Now PLTS' industry-proven performance analysis abilities extend to CDMA devices optimized for commercial LBS applications.

"Evaluating commercial LBS on live networks lacks repeatability and visibility into performance issues," states Chris Ackermann, wireless location test product manager at Spirent Communications. "For LBS to gain widespread acceptance, performance and interoperability issues must be understood and resolved before deployment. PLTS will assist our customers in identifying and isolating issues more quickly and cost-effectively."

Spirent's wireless test solutions aid in all phases of mobile device and wireless network development and deployment for the world's manufacturers and mobile network operators. Spirent's extensive experience in wireless protocols has led to it being considered the "one-stop-shop" for CDMA handset performance and certification testing. Spirent has leveraged its success in mobile performance and certification testing to bring comprehensive performance analysis to the W-CDMA market. The company's wireless core infrastructure GPRS and CDMA performance test systems help service providers identify performance ceilings, enable vendor selections, and plan network capacity prior to deployment, to facilitate smooth service delivery.

Spirent has helped accelerate wireless service delivery by introducing the first and only solutions to test CDMA, WCDMA and GSM location-capable mobile devices. These systems play a critical role in assisting the validation of emergency services such as the U.S. FCC E911, and in facilitating the roll-out of commercial location-based services.

About Spirent Communications

Spirent Communications (www.spirentcom.com) is a global provider of integrated performance analysis and service assurance systems that enable the development and deployment of next-generation networking technology such as Internet telephony, broadband services, 3G wireless, global navigation satellite systems, and network security equipment. Spirent's solutions are used by more than 1,500 customers in 30 countries, including the world's largest equipment manufacturers, service providers, enterprises and governments. Based in Rockville, Maryland, Spirent Communications reported 2004 revenue of $460 million and has 1,700 employees worldwide. The company is the largest business group of Spirent plc, traded on the London and New York Stock Exchanges (LSE:SPT) (NYSE:SPM) (CUSIP number:84856M209). www.spirent.com. Spirent Communications' sales to the United States government are made through Spirent Federal Systems. www.spirentfederal.com

Spirent Communications, Spirent and the Spirent logo are trademarks or registered trademarks of Spirent plc. All other trademarks or registered trademarks are held by their respective companies. All rights reserved.

This press release may contain forward-looking statements that are based on current expectations or beliefs, as well as assumptions about future events. By their nature, forward-looking statements are inherently predictive, speculative and involve risk and uncertainty because they relate to events and depend on circumstances that will occur in the future. You should not place undue reliance on these forward-looking statements, which are not a guarantee of future performance and are subject to factors that could cause Spirent's actual results to differ materially from those expressed or implied by these statements. These risks include the risks described from time to time in Spirent's SEC periodic reports and filings. We undertake no obligation to update our forward-looking statements, whether as a result of new information, future events or otherwise.