Integration of IP and Trunked Radio Network

The break of the 2 and the 3 century is in telecommunications characterised by an integration of various services that are provided by different networks into a single network. This trend is called service integration or network integration. Currently, this integration is not only focused on research work, but the solutions come to be implemented in practice as well. Service integration results from the user`s demands for providing new services in a currently used network. However, new demands spring from the research results obtained and so service integration is a steadily developing and studied area. Network interconnection is closely limited to network integration. Interconnected networks usually contain a network into which the services are being integrated and a network that was originally intended to provide the demanded services. The new possibilities based on the currently reached results of service integration and the practice has led to research that deals with the integration of a trunked radio network and an IP network. The paper focus on the user facilities connected with voice transmission, which is dominantly used in trunked radio networks. Key-Words: QoS, Network, Interconnection, Trunked, Radio 1 Quality of Service The quality of service (QoS) is very important for service integration. The significance of QoS is still growing and its evaluation is crucial, for example, in setting up new services, in choosing the transmission technology and also in the above integration. QoS is defined individually for various types of network with a given communication protocol. QoS approach is not currently unified for all types of network. The QoS evaluation is not a trivial problem with respect to this diversity. The ITU-T (International Telecommunication Union – Telecommunication Section) progressively issues Recommendations for defining QoS. But these Recommendations as regards defining the QoS are not uniform either. Differences can be found, for example, in considering the user’s subjective QoS parameter evaluation or in the selection of measurement points. A selected set of parameters is used for QoS description. Mutually independent parameters evaluated according to selected reference events are called primary parameters. Primary parameters are organized into a 3×3 matrix (Fig. 1). The main features of the matrix are as follows: each row represents one of the three basic and distinct communication functions (speed, accuracy, dependability); each column represents one of the three possible exclusive outcomes when a communication function is attempted (access, transfer, disengagement). Secondary parameters are derived from these primary parameters. The secondary parameters are used to express the service availability function. A specified availability function compares the values of a subset of primary parameters with the corresponding outage thresholds to classify the service as available (no service outage) or unavailable (service outage) during a scheduled service time. The availability parameters then characterize the resulting binary process, which results in the values: 0 – service unavailable, 1 – service available. Unavailable state of service corresponds to a time when no responses are received and also a time when the service is unacceptable due to low network quality, e.g. a low transmission speed or a huge error rate. QoS is generally divided into two basic portions: quality of service and network performance. The Quality of Service (QoS) deals with describing the network behavior from the user’s viewpoint. QoS is generally defined as an overall service performance effect that determines the user’s satisfaction degree. To evaluate QoS a set of parameters related to service support performance, service performance, service protection and others factors is used. Network Performance (NP) deals with the service provider’s description of network behavior. NP is defined as an ability of a network (or a part of network) to provide services related to the user’s communication. NP is used for network planning, developing and maintenance. NP is generally regarded as the technical part of the QoS.