Terrestrial Trunked Radio Technology - Essay Example

?Running Head: Report on TETRA Report on TETRA Technology in 5 Questions Report on TETRA Technology in 5 Questions Give an overview of TETRA The full form of the term TETRA is Terrestrial Trunked Radio which was formerly called Trans-European Trunked Radio. It is a two way transceiver mobile radio arrangement. It is a European Telecommunications Standards Institute (ETSI) specification and its first version was put forward in 1995. TETRA utilises Time Division Multiple Access (TDMA) technology through which both one point to one point and one point to many point transmissions are possible. (Dunlop, Girma and Irvine, 1999; ET Industries, n.d.) “TETRA offers the automatic operation and frequency efficiency of trunking combined with the terminal autonomy of a conventional PMR1. TETRA has a multi-mode capability by combining these two modes, trunking and direct (conventional), into a single terminal equipment, and it also provides the standardised way of inter-working between these two modes.” (Net Resources International, 2011) TETRA is thus designed to provide bandwidth-on-demand by which a variable quantity of bandwidth can be allocated for the call duration as per the application conditions set. TETRA functions through reference points and functional configurations, and flexibility of standards is maintained inside the network environment. (Dunlop, Girma and Irvine, 1999) TETRA has wide spectrum utilities and it is perhaps best suited to establish critical mobile radio networks capable to handle emergencies. Who use it and why is it used? The technical specifications provided by TETRA are actually guided by a comprehensive set of end user necessities. As a result “most of the potential user groups of this network technology have been identified from the inception of the standard. Communication features such as group call, Direct Mode Operation, and numerous emergency-oriented supplementary services are all driven by end user demands during the standardisation process.” (Dunlop, Girma and Irvine, 1999) In such a state of affair, TETRA has scope for both the individual users and a wide variety of user groups. TETRA user groups are described below: Table – 1: TETRA User Groups Source: Dunlop, Girma and Irvine, 1999, p. 162 Inclusion of so many user groups in the TETRA networking realm proves that TETRA is extremely useful, flexible and dynamic. The main reason of popularity and diverse usability of TETRA is its multiple application support. “TETRA supports point-to-point and point-to-multipoint communications both through the TETRA infrastructure and by use of direct mode without infrastructure.” (Net Resources International, 2011) To this extent TETRA can use applications like Voice over Internet Protocol (VoIP) too. For non-voice applications, the major application types of TETRA are video and multimedia application and data-oriented application. Moreover, it is interoperable with GSM, CDMA, UMTS, etc. network architectures. (Plans, Paradells and Gomez, 2006) What are the TETRA components systems? “Most system descriptions are based on a conceptual representation of functional configurations and reference points, which is a widely adopted methodology of describing the interconnections of components within a network system.” (Dunlop, Girma and Irvine, 1999, p. 161) Using this approach, it becomes essential to understand the interfaces in the TETRA standard. These interfaces through which TETRA components systems inter-communicate are described below: Figure – 1: Interfaces in the TETRA Standard Source: Bekkers, 2001, p. 382 Moreover, the standards for TETRA are related only with the peripheral environment of a TETRA system, referred to in the standardisation guide as Switching and Management Infrastructure (SwMI). Figure – 2: Functional Network Configuration of a TETRA SwMI Dunlop, Girma and Irvine, 1999, p. 164 With the help of the above network configuration diagram, we can find out six principle TETRA components. These are network management unit, gateway, direct mode mobile station (DM-MS), line station (LS), mobile station (MS) and the individual TETRA network. All these components and the interfaces among them can be subjected to TETRA standardisation. Only the internal settings of an individual TETRA network are exception to this rule. Moreover, the gateways may use circuit switching technology or software enabled switching technology. A combination of these two technologies can also be put in implementation. In this way TETRA component system is suited for high speed internetworking and older but robust backup techniques. What are the modes of operation and performance capabilities and the technologies that underpin it? When a network is absent the TETRA portables/mobiles can utilise direct mode through which they can share the channels directly. With the help of gateway mode a single TETRA portable/mobile (with a network connection) can function like a relay reference point for the other TETRA portables/mobiles which are out of the network range. Moreover, there are various fall back modes that help TETRA to be implemented for developing the most critical networks like those of the emergency services. The sub-interfaces of the TETRA air interface with reference to the various operational modes are shown below: Figure – 3: Sub-Interfaces of the TETRA Air Interface with Reference to the Various Operational Modes Source: Bekkers, 2001, p. 384 The most important performance capability of TETRA is its interoperability with other network infrastructures. Salkintzis (2006) has chosen Wireless Local Area Network (WLAN) to explain this performance capability, where the WLAN radio access network interoperates with the conventional TETRA terminals and can make use of “all TETRA services, including group calls, short data messaging, packet data, and so forth. In addition, however, such terminals can support a range of brand new capabilities enabled by the WLAN, such as broadband data services, true concurrent voice and data services, simultaneous reception of many group calls, reduced call setup and voice transmission delays, improved voice quality, and so forth.” (Salkintzis, 2006, p. 38) DNS, IP multicast and VoIP are the main technologies that underpin these capabilities. Moreover, Frequency Division Duplex (FDD) technique and FDMA/TDMA provide TETRA with powerful radio aspects. Benefits and drawbacks of TETRA compared to commercial mobile telephony systems including key security issues. Benefits: 1. TETRA has lower frequency and hence longer range. It has very fast rates of call setup ( Read More