TETRA Experience 2006 CongressWarsaw, June 13-14, 2006 Trunked Radio Dispatcher System for the Polish Power Energy Distribution Companies - Case Study Authors: Jerzy Andruszkiewicz Stefan Wieczorek
Dispatcher radio system for distribution companies – basic requirements • Assuring of energy safety of the country and proper functioning of technical services requires independent dispatcher radio system for support and maintenance of the power distribution system – the system should have specific dispatcher functions and should work in emergency and critical states. • Existing networks of public operators do not assure proper work in emergency and critical states, they are not resistant to extreme hazard conditions, they do not cope with special dispatcher functions and are not resistant to sudden traffic increase.
Resources of distribution companies: Infrastructure of analog radio network – Digicom 7 • 431 base stations, in particular: - 400 have their own antenna masts (40 and 60 m above terrain level) localized in own premises • - 31 localized in leased premises • Radio Base Stations (RBS) are connected with Central Nodes (CN) of each distribution company (ZE) by means of mainly own analog and digital (fiber optic) links. • Radio channels in the 410 - 430 MHz band (12,5 kHz)
Radio coverage of the analog network used by the distribution companies in the 410 - 430 MHz band: – approx. 80% of Poland’s area, - 31 local networks belonging to the distribution companies (ZE) and one interregional network (Mazovian group), - the national network does not exist (including corporation networks in the new distribution companies’ structure) - approx. 75% of own links connecting RBS with CN
BS sites of the analog dispatcher radio system for power distribution companies in Poland
Tests of digital radio networks in distribution companies The comparison tests of radio coverage for analog system and two digital systems (TETRA, P.25) have shown that effective coverage is comparable for all systems (for minimum electric field intensity values required for proper work in the distribution company network). It means that existing BS sites can be used together with new sites filling the gaps in coverage (approx. 150-160 new sites). It will allow to minimize additional capital expenditures.
Present and future needs of radio system users: - voice communications – voice transmission, - high speed data links, - better coverage, - access to the national radio system and to other networks, - higher level of data confidentiality and work security in the network, - dispatcher network functions, including service priorities, - the system should be independent of other radio networks – easy access in emergency conditions (high traffic).
Concept of building the common radio network for many users: - possibility to use one radio system by many users having different services, transmission security measures and privacy, - reduction of the unit cost of system purchase and unit maintenance cost (per one user), - optimum use of the system resources, - effective use of the frequency band and spectrum management (esp. with 12.5 kHz raster), - effective use of human resources for system maintenance.
TETRA network user groups – shared resources Independent VPNs
Most important reasons for power distribution radio system digitalization • Transition from analog to digital systems is obligatory due to the national regulation body (UKE) policy and international agreements. • Radio transmission permits obtained by the power distribution companies will expire in a few years. • Users have new demands coming from the technology development (most of them requires digital transmission). • IP protocol allows convergence and integration of various transmission media. • Outdated and run-down existing equipment must be replaced.
Digitalization of the radio system for the power distribution companies will allow: • Optimum usage of the allocated frequency band • Effective usage of existing technical resources – BS infrastructure and digital links, • Reduction of capital and maintenance expenditures for the new network, • Scalability of the radio system, • Tailoring the system to the changing users’ needs, • Independent and safe work of the radio network in emergency cases, • Cooperation of the users’ groups created ad hoc during disasters of any type and cooperation with other emergency services, • Protection and confidentiality of transmitted data. • Access of other cooperating users (e.g., PSE, cooperating companies) to the network resources as VPNs.
Expected effects of radio network digitalization • Optimum usage of the allocated frequency band via optimization of BS sites – BSs in the border areas between neighbouring distribution companies will be removed • Maximum usage of existing infrastructure belonging to distribution companies • Better coverage due to 30% increase of BS’s number • Improvement of service quality and digital transmission of data
Project of the final system configuration KONSOLA BTS BTS BTS BTS PSTN BTS Tetra network • NETWORK • MANAGEMENT • STATION PABX • NETWORK • MANAGEMENT • SERVER DISPATCHER’S CONSOLE
System architecture – main aspects • Integration of the radio system based on IP architecture • Most favorable variant – development of corporation networks being the elements of the national network • System integration with PSTN, PABX, public GSM and UMTS networks • Possibility of emerging independent VPNs for various related users, • Access to internal departamental IT resources • Network reconfiguration possibility depending on the current needs
Summary (1): • Due to the increasing demand of the power distribution sector, esp. for the data transmission, and due to the state of the existing analog network, it is absolutely necessary to begin actions resulting in network modernization and improved quality of services. • Analysis of the digitalization possibility of the power distribution companies’ dispatcher radio network shows that digitalization based on the existing IT resources is possible. • It is necessary to establish the rules, organization scheme and the development possibility of the digital radio network together with other potential users in Poland • It is necessary to develop detailed technical and financial analysis, feasibility study, technical projects and to raise investment funds.
Summary (2): • It is possible to optimize development costs of the radio network due to the existing infrastructure of the distribution companies, allocated frequency band and building a nationwide network • It is necessary to find the strategy for further activities in the area of using the existing resources, finding new finance sources necessary for modernization or development of a new network and cooperation with other users. • An independent dispatcher radio network is a guarantee that the Polish power distribution system will work correctly and safely.