As the mobile industry is ramping up at ‘full speed’ to deploy LTE networks, the test industry is preparing to respond to the issues faced by operators/users when a new mobile network is launched. These are the stability of the devices, and the quality of network coverage.
It was a clear experience from 3G that lack of coverage, and unstable handsets were two key customer experiences that slowed the take up of the new technology.
There has been much activity in the industry to prepare the test cases for certification of handsets, as these are used as a baseline to confirm stability and operation of handsets. Whilst there was a delay in the test cases for the launch of 3G, there seems to be much better preparation for LTE.
The industry bodies (3GPP, GCF etc..) have prepared test cases, and leading chipset/device manufacturers are now working closely with test equipment vendors to de-bug and verify these test cases so they can be used for device certification.
These test cases and test equipment will be on live demonstration in at Mobile World Congress in Barcelona this month to show the industry progress towards this important milestone.
A second key aspect of device stability learnt from 3G is that often the certification test cases are not enough for an individual operator, who has network specific issues to verify.
In this area, the test equipment vendors have been working directly with the with the network operators to define test environments that can re-create these network specific issues, and therefore test the devices to ensure correct operation. The development of new test case programming/editing environments has been a key issue here, as the traditional TTCN based approach for device certification is not well suited to this application.
Instead, the focus is on more graphical and inter-active software for test environments, which allow a network engineer to operate and verify tests rather than require a dedicated TTCN programming engineer.
In the area of network coverage and quality, the key issue is for an operator to measure the actual coverage/quality to be sure that expectations are met, and then to monitor the radio network operation to catch any issues quickly before they affect user experience.
The high costs of ‘drive test’ systems that were used in 3G will need to be avoided for LTE, as the deployment and operational budgets of the network will be under tight control for LTE. To replace ‘drive test’, the industry has a new technology, SON, which allows the network to administer itself and automate configuration/control.
To trouble-shoot these complex ‘automated’ systems requires more complex test tools to make detailed RF measurements on the configuration and operation of the basestation site ‘over the air’ as well as directly connected to the base-station.
Author is Jonathan Borrill of Anritsu
Mobile World Congress takes place in Barcelona between 15-18th February