DECT as a radio technology was first introduced by CEPT (Conférence Européenne des Administrations des Postes et des Télécommunications) in 1993, a quarter of a century ago! For many years manufacturers of chips and systems focused on voice applications, for which its founding fathers had optimized the technology. Even its original name stood for Digital European Cordless Telephony, which was later renamed to Digital Enhanced Communications Technology. The DECT brand belongs to the European Standards Institute ETSI. Since it’s standardization, DECT operates on its own dedicated radio frequency band in Europe between 1880 MHz and 1900 MHz. In an age of multiple competing short range radio standards, this is indeed a unique and significant selling proposition.
DECT based devices still enjoy a stable market position with about 100 Mio devices sold annually in the global professional and residential small cell telecommunication sectors. However, telephony markets no longer offer that kind of growth. In an era of IP based telephony, (DECT also features strongly here with CAT-iq-Cordless Advanced Technology- Internet and quality since its introduction in 2006), the classical DECT telephony market has been increasingly penetrated by more powerful Wi-Fi and cost competitive mobile phones.
openD Development KitsThe development modules of the semiconductor manufacturers Dialog Semiconductor and DSP Group are already supported by the openD prototyping platform.
For this reason, the DECT industry started the process of becoming a data communication technology at an early stage by introducing several technical measures. The first conducted tests for these measures however were mainly for multimedia applications. In 1998 the DECT Packet Radio Service (DPRS-ETS 301649) which is used for packet oriented data communications services like service negotiation (SN) and reliable quality of service (QoS) was extended to include Dynamic Resource Management (DRM) to efficiently deal with bursty data traffic. In 1999 the DECT Multimedia Consortium (DECT-MMC) was founded to challenge the might of Wi-Fi and Bluetooth.
With ULE, (Ultra Low Energy) this positioning has been far more successful, concentrating on low data rates with extremely efficient power consumption. ULE was first introduced in 2011. In 2013 the ULE Alliance was founded as a separate organization with its own brand. ULE devices do not require a new fixed part and work seamlessly with legacy DECT and IP based base stations, meaning existing installations such as the Fritzbox 7xxx series from AVM or Deutsche Telekom’s Speedport Home Gateway family can be used with the additional advantage of offering internet connectivity. In the meantime there are many commercially available ULE clients (Portable Parts) especially in the area of home security and automation (eg. Remotely controllable smart plugs, movement-, and smoke sensors as well as door communication systems.
The Platform simplifies the developer’s task
In spite of the continued success of products in these markets, DECT and ULE based developments have also attracted growing interest of developers in professional and more complex application fields.
To enable easier entry for developers, especially for small businesses and SMEs in diverse application markets, like industrial automation, DECT Forum has created a chip independent developer platform with a generic set of interfaces (APIs: Application Programming Interfaces) for base station and client.
The developer platform is called »openD« , can be licensed under Apache 2.0 or a GPLv2 license and is available on GitHub at (https://github.com/opend-connect). The openD prototyping platform SW architecture can be seen in figure 1. It contains the following hardware elements.
- For the base station (FP: Fixed Part), a Raspberry PI compatible MMI module and a DECT transceiver module from Dialog Semiconductor or a DECT USB Transceiver from the DSP Group.
- For the Client side (PP: Portable Part): a STM Nucleo compatible MMI module as well as a DECT transceiver module from Dialog Semiconductor or a compatible DECT Transceiver Module (Shield) from DSP Group.
A generic API (openD- API) is available for both sides with the following functionality:
- Management (mgmt): Functionality for the administration of the device (eg. Keep Alive message or energy management).
- Subscription (sub): an interface for the registration / deregistration of devices. Access codes can also be configured here.
- Call (call): enables call set up and disconnection of line switched connections (eg. Telephone calls).
- Audio (audio): delivers an interface for the control and use of audio transmission.
- HAN-FUN (hanfun): the Home Area FUNctional protocol(HAN-FUN) enables the interoperability of devices from different manufacturers not only purely on the transport level but also on the application level.
- 6LoWPAN (sixlowpan): Within the framework of the ULE specification an integration of the 6Lo-Protocols according to IETF RFC 8105 for the display of IPV6 traffic was specified for the ULE link layer. An open source implementation is also available for this and can be found on Git Hub at https://github.com/ULE-Alliance/ULE_6LowPan.
The documentation of the openD Architecture and the interfaces is available on the public domain at https://github.com/opend-connect/openD. DECT Forum commissioned Stackforce GmbH with the development of openD. More information can also be found here http://stackforce.github.io/opend-doc/.
The author would like to express his gratitude to those behind the development of openD platform. DECT Forum (Daniel Hartnett), as well as to Daniel Jäckle, David Rahusen and Patrick Weber from Stackforce for their support on this article.
Prof. Dr.-Ing. Dipl.-Ing. Dipl. Wirt.-Ing. Axel Sikora
Academic Director of the Institute for Reliable Embedded Systems and Communications Electronics (ivESK) in the University of Offenburg, Divisional Head of Software Solutions and Deputy Head of the Institute at the Hahn Schickard Company for applied research in Villingen-Schwenningen, as well as founder and owner of Stackforce GmbH.
His teams work on algorithms, protocols and systems for secure, reliable and efficient wired and wireless communication applications as well as their evaluation, implementation and verification.
He also serves on the academic advisory committee for the WEKA publishing House for their Wireless Congress and IoT conferences. In addition, Dr. Sikora acts as Deputy Chairman of the Embedded World Conference.
|Einstieg in openD|
On the 25.2.2019, openD will be officially launched by DECT Forum, the day before the Embedded World Conference in Nürnberg. The launch will take the form of a conference with speakers in the morning session from key DECT and ULE system manufacturers with applications in voice and data communications. The afternoon session will feature a hands-on tutorial with demos and a walk-through of a sensor application design with 10 Demo stations planned with equipment from both chip manufacturers. In the tutorial the tooling, debugger, code editor and the whole development process will be demonstrated.
|Wkat: OpenD Conference|
|Who: DECT Forum|
|When: 25.2.2019 (9:30 – 18:00)|
|Where: Nürnberg, Fraunhofer IIS, Nordostpark 84|
|Entrance: Free of Charge. Registration required