Digital readiness NGNs
Next Generation Networks
The following should provide clear advice on the action you should take when encountering NGNs and enable you to ensure the most appropriate telecare devices are being deployed.
What is a NGN?
Until recently companies such as Sky and Talk Talk have acted simply as telephone call resellers enabling them to bill customers directly for telephone calls made whilst the user continues to pay BT for telephone line rental. However since OFCOM’s decision to increase competition in the telephone market there has been an increasing number of suppliers offering full telephone services in the UK. These suppliers are now starting to roll out their own networks (NGNs) enabling them to offer services independently of BT’s network including the billing of the customer’s line rental.
BT was also planning to implement a new digital network - referred to as 21CN (21st Century Network) - across the whole of the UK, starting in South Wales. The new network was designed to support BT's roll out of internet based TV, higher speed broadband and other new digital services and involved the planned migration of every UK voice line alongside the introduction of a range of new services.
How does a NGN affect telecare/social alarms?
21CN was designed to use an IP core based network with different equipment in the local exchanges. This introduces certain slightly changed network characteristics such as increased round trip delay. As such when implemented, some older social alarm equipment/protocols may not function reliably, particularly where dependent upon specific transmission time delays across the network. The issues seen with social alarm equipment during testing include:
- Alarm activation (from a telecare sensor/personal trigger/red button) may not raise an alert at the monitoring centre
- Equipment Failing to open a speech path
- Equipment dropping calls
- Incomplete information presented to the monitoring centre
How has telecare/social alarm equipment been tested?
When Tunstall became aware of the effect IP technology can have on DTMF protocols it firstly worked with BT to test current Tunstall DTMF protocols, to confirm the extent of any operational impact ( Click here to view the test results ). Tunstall also went on to develop a new protocol signalling method, known as Sequential/Single Tone Multi Frequency (STMF), to overcome the DTMF interception problems apparent in some NGN networks.
The patent-pending STMF protocol was tested on mobile networks and has proved to be reliable even where DTMF protocols had been shown to fail. As a result, Tunstall launched the Lifeline Connect+ (GSM compatible) home unit that utilised the new STMF protocol initially to ensure GSM network compatibility. This STMF communication method has also been tested successfully in several European countries where digital home connections are more prevalent.
More recently, Tunstall has carried out testing of both the DTMF and STMF protocols with the Sky and Talk Talk networks. These tests show that whilst no complete failures occurred the DTMF protocol does on occasion have to retry in order to successfully communicate with the monitoring centre. Whereas the STMF protocol performed resiliently and successfully transmitted first time on all tests.
What steps are social alarm providers advised to take?
Network providers are unable to guarantee the compatibility of equipment on their networks and often advise social alarm service providers to seek advice from their equipment suppliers as to how they might be affected, due to the life critical nature of the equipment. It is recommended that customers review the Tunstall equipment testing results and their accompanying explanations to determine whether there may be an issue with equipment currently being used.
In addition, where telecare users are already using NGNs or may use one in future, Tunstall advises that the STMF protocol should be used (for more detail on STMF please click here ). It is also important to ensure a regular test regime, in line with TSA guidelines, is in place.