TETRAPOL ADVANTAGES USER BENEFITS TECHNICAL ASPECTS Multi-site Open Channel Immediate channel access can be guaranteed to a group of users over a wide area, even when the system is heavily loaded or even congested, like during natural disasters or major accidents Multi-site Open Channels (MOCH) can be used as mutual-aid channels where different pre-defined organizations can communicate with each other For instance Police officers and firemen can coordinate their actions at the scene of a fire Multi-site Open Channels can also be set-up for the exclusive use of one organization· Multi-site Open Channels can be set up upon request to respond in real time to operational requirements, planned or unexpected A radio channel can be temporary dedicated to a group of users for the whole duration of their mission (whatever the duration) Authorized users of a given MOCH are one or several operational groups defined as one of the MOCH attributes The exclusive use is defined over one or several radio cells Resources are put back to the pool of channels as soon as the MOCH is closed by an authorized user Talk Group Messages exchanged within a group of users do not mix with messages exchanged within another group, therefore eliminating any risk of confusion or even 'distraction' People can not overhear communications which have nothing to do with their business. For instance traffic police officers will not monitor criminal police communications A Talk Group is defined as a group of terminals and a geographic area (ie radio cells) where it is valid A user can be member of several talk groups Scanning Users can monitor communications of several groups alternately. For instance the chief of a Police Department may want to monitor communications of different units Supplementary service of the protocol Talk Group Merging This powerful feature can be used upon request to allow immediate communications between teams who are not communicating with each other under normal circumstances. For instance, when police and firebrigades dispatched to the scene of an accident need to coordinate their actions This greatly facilitates multi-disciplinary communications Supplementary service of the protocol Dynamic Group Number Assignment When people in the field are assigned to a new mission, their TETRAPOL radio terminal can be dynamically updated over the air so that they can participate to the communications resulting from this new assignment. This means high flexibility and responsiveness regarding operational changes as people are not anymore constrained to a limited number of talkgroups pre-programmed in their radio terminal For instance a fire engine reporting to district 1 can be unexpectedly dispatched to a forest wildfire in district 2: even if its radio terminal would not allow 'district 2' under normal circumstances, it is possible to reassign it to 'district 2' over the air. Supplementary service of the protocol Individual call 2 persons located anywhere within the coverage of a TETRAPOL system can have a private conversation without the rest of their group monitoring the communication For instance, in a statewide TETRAPOL system, a superintendent in one county can have a private conversation with a superintendent in another county. And an inspector going out of his jurisdiction for an investigation is still reachable from his normal jurisdiction. Priorities can be used to interrupt an on-going private call The feature can be enabled/disabled on a per-user basis (defined in the user profile) Multi-party call A private conversation can be extended to up to 5 parties (similar to a telephone conference call). Location registers are used to find the called parties anywhere within the system PABX/PSTN call (telephone interconnect) People in the field can receive or place telephone calls from their TETRAPOL terminal This can eliminate the need to find a telephone booth or to have an additional mobile phone when they have to reach people who are 'external' to the TETRAPOL system (off-duty, outside the coverage of the system, not eligible to use the system, ...) Calls can be authorized by dispatcher prior to their establishment for a better control of this service For instance the PABX of an hospital can be connected to a TETRAPOL system so that rescuers at the scene of an accident or disaster can call physicians or any emergency personnel of the hospital, on their telephone extension. PABX/PSTN gateway· The feature can be enabled/disabled on a per-user basis (defined in the user profile) Calls can be unconditionally routed to dispatcher first Call forwarding Calls can be automatically rerouted when people are not available For instance a police officer leaving his car can forward all his calls from his mobile radio to his portable radio Supplementary service of the protocol Call transfer This feature is similar to telephony and can be used to control the establishment of certain types of communications (for instance inbound/outbound telephone calls) by authorized individuals (typically dispatchers). They act as 'operators', connecting two parties upon request from one of them. Supplementary service of the protocol Priority levels Priority levels make sure that important calls are always treated first in case of system congestion. These priorities may reflect a hierarchy (among people, among departments) but also an operational situation requiring a special treatment of the call whatever the hierarchy of the person. This second aspect is important in situations such as a superintendent making a routine call vs a traffic police officer making an urgent call to report an accident. Priority should be given to the traffic police officer although individually ranked in the system below the superintendent. TETRAPOL makes this kind of discrimination possible. Supplementary service of the protocol Combination of priorities:· User priority Talkgroup priority Recent-user priority Preemption priority Retention priority User-selectable call priority ... Pre-emptive emergency call In the most critical situations, when life is at risk, users can always call for help. Even if the TETRAPOL system is already fully used, the message get through at once, cutting ongoing communications if necessary. Colleagues or dispatchers can be immediately notified of the situation and can help. Frame stealing is used on a traffic channel to force transmitter interruption and to re-allocate the resource to an emergency call Various parameters are available to adapt to different operational requirements for handling an emergency call (people receiving the call, single-cell or multi-cell call, ...) Ambience Listening Transmission can be remotely and discreetly activated on a TETRAPOL radio terminal. This means for instance that a dispatcher who gets no answer or no news from a radio terminal can monitor what is going on (shots, voices, etc...). This is an important feature when people are unable to use their radio, like when they are under attack, held hostage or simply injured. Supplementary service of the protocol Direct-mode (ie 'simplex' channels) emergency call Emergency calls can be placed even in areas where coverage from the system was not needed or planned (for instance in far remote areas). A person in a critical situation can always get help from colleagues within radio coverage, even from those who were not on the same direct mode channel (people do not have anymore to switch from channel to channel before they can find somebody). For instance, when several teams work separately at the same place, each using its own direct mode channel, this is a powerful feature to warn everybody if something goes wrong. Direct Mode Emergency Frame transmitted on a pre-programmed channel monitored by all radio terminals Direct mode with dual watch Users who have switched to direct mode channels are not isolated from the radio network and from their dispatchers as long as they are within the coverage of the TETRAPOL system. Dual watch mechanism so that control channel is still monitored to detect incoming calls Late entry A user does not miss ongoing communications even if he arrives late in the TETRAPOL system (like when getting out of uncovered areas such as underground car parks, etc.) or if he was already engaged in a different call. Supplementary service of the protocol Talking Party Identification Radio ID can be sent on each Push-To-Talk activation so that a transmitting terminal can be immediately identified. This helps dispatchers avoid confusions. This also dissuades any misuse of the system. Supplementary service of the protocol End-to-end encryption Communications are protected from commercial and more sophisticated scanners Communications are encrypted within the whole system: there is no weak segment where communications are transported in clear mode (for instance between a switch and remote dispatcher consoles, or between repeater sites and switches): this gives the highest level of protection against eavesdropping. Repeater sites do not need extra-protection since they do not need to include encryption modules Encryption algorithms compliant to the TETRAPOL specifications or specific algorithms can be used Secured Over-The-Air key distribution Key loaders are not used anymore to change encryption keys in the radio terminals this eliminates many important issues associated to key loaders like errors when downloading new keys, missed terminals, loss of sensitive programming devices used in the field ... Keys can be renewed and downloaded in the terminals with a very high periodicity (typically daily) whatever the size of the fleet of terminals in the field It is not necessary to bring all radio terminals back to reprogam the encryption keys, therefore saving time and eliminating downtime and users'disruption. Key management center New encryption keys are automatically and periodically distributed to the terminals. Keys are distributed over-the-air in an encrypted format and following authentication procedures User-friendly encryption mechanisms Users do not have to remember key selections, whether for voice or for data communications: this is done automatically by the system. They can fully concentrate on the operational aspects of their missions, and do not have to worry about the 'technical' ones. Encryption is maintained and automatic while the terminal roams through a nationwide system. For instance, with a nationwide TETRAPOL system, Narcotics Officers can keep end-to-end encrypted communications anywhere and at any time without having to do any manual action on their radio terminal. Encryption can be activated in direct mode but it is a voluntary action from the users. Mutual authentication A TETRAPOL system is protected against sophisticated smart attacks, such as the intrusion of unauthorized terminals by 'masquarading' or the use of a 'decoy' infrastructure. Mutual authentication between system components Challenge response mechanisms Protection against lost or stolen terminals Lost or stolen TETRAPOL terminals can be 'neutralized' over the air, either on a temporary basis (i.e. the terminal can return to normal operation after it receives the right command from the system) or on a permanent basis (i.e. requiring subsequent maintenance of the terminal): terminals falling into 'enemy' hands can be neutralized. When terminals are lent to an organization hosted on a TETRAPOL system for the duration of a special event, they can be disabled as soon as the event is over and even before they are returned. This guarantees a strict control of their use. If the radio terminal was switched off, it is disabled as soon as it is switched on (at the next registration transaction) Virtual Private Networking Different organizations can share capital expenditures and running costs while getting a better common system Each organization keeps its full operational and tactical independency, and its privacy Communications between organizations are possible when required and if authorized at the system level higher operational efficiency and responsiveness during mutual-aid operations A TETRAPOL system can reflect the administrative structure of each organization hierarchical, functional, jurisdictional Each organization can have a guaranteed quota of resources available even when the system is heavily loaded, like during natural disasters or major accidents Technical, tactical and operational management functions are addressed separately Tactical and operational functions are managed by each organization, technical management functions are under the system 'operator' responsibility Common platform for voice and data communications Same infrastructure and radio terminals are used for voice and data communications: Simple solution for the users as they do not have to switch between voice and data channels, or between voice and data terminals. Vehicles and radio sites are not overloaded with equipment Costs can be saved on spare parts training of maintenance personnel system supervision· installation & maintenance site equipment and radio terminals Integrated voice and data solution Mobile data Databases can be accessed and updated in real time from the field, eliminating discrepancies or interaction from a third-party. People are relieved from paperwork in the field as they can immedialtely update databases, send reports, etc. Voices messages are prone to misunderstandings, especially in a noisy environment. Data messages are not: people always get the right address or the right name ! A data transmission can be much richer than a voice communication as it may include maps, text, pictures, etc.: people in the field can get more information about their assignments, which can mean both increased safety and effectiveness Voice traffic can be reduced, in turn reducing the background noise for the radio operators, in cars or in control rooms, letting them concentrate on the important radio traffic Information is distributed much more selectively: only people who read the message know it, whereas a voice message can be overheard by a lot of people including those who should not hear it (ex: a suspect hearing the communications about his criminal record while in a police car) Information can be stored if the addressee is not available, whereas a voice message would have to be repeated later. For instance, with data communications, people going back to their car get messages immediately. Integrated data services· electronic mail status· short messages (SMS) IP Standard data interfaces API (Application Programming Interface) are available for the development of specific data applications Connection to other telecommunication networks A TETRAPOL system can be a prolongation of an existing information system past investments can be preserved field personnel can get access to information systems they are already familiar with People in the field get a real 'mobile office' they do not have to return to their office before they can accomplish their daily office work (job tickets, database queries, e-mails, reports, ...) TETRAPOL specifications include various gateways to other networks (to other TETRAPOL networks, other PMR networks, Packet Data Networks, PTSN/PABX networks, ...) Consistent audio quality over the whole coverage A TETRAPOL system can be a prolongation of an existing information system past investments can be preserved field personnel can get access to information systems they are already familiar with People in the field get a real 'mobile office' they do not have to return to their office before they can accomplish their daily office work (job tickets, database queries, e-mails, reports, ...) TETRAPOL specifications include various gateways to other networks (to other TETRAPOL networks, other PMR networks, Packet Data Networks, PTSN/PABX networks, ...) Similar audio quality in clear and encrypted modes As encryption does not degrade the audio quality, users activate it whenever required, protecting their lives and/or their missions Encrypted voice is always received crisp and clear: it does not reduce the efficiency of the users as repetitions of messages are not necessary. Excellent speaker recognition helps team members engaged in a critical operation communicate quickly with each other, without having necessarily to identify themselves each time they talk. The voice is already transmitted in a binary format in clear mode. As the digital encryption is applied to an already-digital information, it is not noticeable by the user. High performing vocoder in noisy environments Noisy backgrounds (shouting crowds, fire engines, sirens, ...) are suppressed from the transmissions this eliminates the audio 'discomfort' created by these interfering background noises Messages are received crisp and clear all the time, avoiding repetitions or misunderstandings this means greater efficiency and less stress put on the radio operators RP-CELP vocoder 14 Mips Flexibility / modularity TETRAPOL systems can adapt to / grow with organizations since· local to nationwide systems are possible star, daisy-chain, and meshed topologies are possible Local systems can be interconnected later on into a seamless system TETRAPOL specifications leave open the size and the topology of the systems developped by the manufacturers Larger radio coverages than competing solutions => fewer repeater sites are necessary to cover a given area Large radio cells are available for rural areas where dense cellular architectures are not an economically viable solution Time can be saved on system engineering, installation and maintenance activities: wide-area systems can be set-up more quickly Costs can be saved on system engineering, installation and maintenance leased lines site rentals civil work site equipment Finding repeater sites is not an issue when going from analog to digital: system operators can reuse their existing analog sites without having to add new ones and can even reduce the number of sites in some cases. Oustanding sensitivity (-121 dBm) thanks to narrow channels (12.5 kHz) robust modulation (GMSK) sophisticated channel coding (FEC) including block coding, cyclic coding and interleaving· coherent demodulation non-transparent base stations non-transparent packet data transmissions Sensitivity can be even further enhanced with antenna diversity techniques RF power amplifiers with high efficiency (Class C) Same radio coverage for voice and data communications, whether clear or encrypted Users do not have to worry anymore about getting a good signal from a repeater before transmitting data or encrypted voice: they get an efficient and reliable communication tool whenever required Different codings for voice and data, with a much stronger protection for data Non-transparent packet data transmissions Residual error rate (ie quality) is the prime concern in a TETRAPOL system, not raw data rate Data transmissions do not require additional sites Radio engineering is identical for voice and data communications, whether clear or encrypted: easier, quicker and cheaper engineering The later introduction of data services, or encryption, in a voice system does not require to re-engineer the system (from a coverage point of view): systems can be upgraded smoothly Different codings for voice and data, with a much stronger protection for data Non-transparent packet data transmissions Residual error rate (ie quality) is the prime concern in a TETRAPOL system, not raw data rate Spectrum-efficient solution Users get more traffic capacity within the same amount of radio spectrum. This may eliminate channel congestion problems. As an example a TETRAPOL solution can more than triple the traffic capacity that would be available with a 25 kHz analog wide-area system. 12-cell reuse pattern thanks to an Carrier-to-Interference ratio (C/I) of 15 dB Simulcast capabilities· Trunking techniques 12.5 kHz minimum requirement in all configurations (direct mode, repeated direct mode, trunk mode) Trunking (automatic and dynamic allocation of system resources) People do not have to think in terms of radio channels anymore. Operational entities are the only things they have to be familiar with for their communications (like 'traffic police', 'criminal police', 'fire department', 'chief' etc.). They get a more user-friendly tool as they do not have to select radio channels anymore, whether for voice or for data transmissions, clear or encrypted they do not risk to select or stay on the wrong channel they do not notice the failure of a radio channel (as another one would be automatically allocated by the system) Trunking of resources is part of the system protocol (message trunking, quasi-transmission trunking) Simulcast capabilities Systems can be rolled out even when few channels are available, like in most big cities With a simulcast configuration, moving from one radio cell to another is totally imperceptible for all the people involved in the communication. For instance, with a simulcast TETRAPOL system installed along a highway, highway patrols involved in a common operation over tens of miles will have uninterrupted communications, although they may be quickly crossing radio cells A radio cell can be extended to difficult areas (for instance behind an artificial screen like a group of buildings) where there is no radio coverage otherwise The limited impact of inter-symbol interferences in a TETRAPOL system eases the engineering issues of simulcast configurations Cellular radio coverage Local and individual communications can be better distributed among / confined within radio cells, the overal system capacity is increased traffic within one jurisdiction does not disturb traffic within an adjacent one Cell sizes can be adapted to the type of coverage (mobile or portable) better grade of service TETRAPOL is based on a cellular-architecture concept 12-cell reuse pattern with C/I = 15 dB Mixing pure cellular coverage and simulcast is possible· Late-entry service Controls channels broadcast information about neighbouring cells Seamless Roaming Users do not have to worry about channel selection or repeater coverage while roaming within the system A dispatcher is always able to reach people in the right cells, even when they leave their jurisdiction Cellular concept with mobility management Home Location Registers, Visitor Location Registers Registration mechanisms with attach/detach Cell Selection / Reselection mechanisms Late-entry service 12.5 kHz solution TETRAPOL systems can easily fit in current PMR frequency plans and rasters without prior spectrum refarming, which is always a complex and lenghty process Analog channels can be easily converted into digital channels: system conversion can be planned on a per-channel basis and an analog repeater can be simply swapped for a digital one Simple system configurations (Direct Mode, Repeated Direct Mode) do not require more than 12.5 kHz GMSK modulation with BT = 0,25 GMSK modulation Even clear communications can not be monitored with commercial scanners (digital radio transmission) Easy implementation of high-output RF power amplifiers increases possible radio coverages GMSK with BT=0,25· Constant envelop Class-C RF power amplifier Power in adjacent 12.5 kHz channel: - 60 dBc (-70 dBc in an adjacent 25 kHz channel) FDMA on narrow channels Large cells are available for rural areas, reducing the number of repeater sites needed to cover a given area Simulcast configurations are possible saving radio channels when required allowing fully-transparent hand-overs Good intrinsic protection again the loss of a radio channel (shutdown, jamming, failure, ...) at a repeater site It only slightly reduces the overal system capacity (loss of one communication resource only) compared to a TDMA system where several communication resources are lost when a radio channel is inoperative (ex: 4 with Tetra). Direct mode (ie 'walky-talky' mode) is higly-reliable The same radio terminals can be used in any environment (urban areas, hilly terrains, simulcast systems, ...) Limited impact of inter-symbol interferences No equalisation required in the TETRAPOL radio receivers Receiver noise limited due to the use of narrow channels No tricky multi-slot synchronization constraints Peaceful coexistence with other PMR systems Radio spectrum can be used at best (no need to leave radio channels unused between existing ETS 300-113 systems and new TETRAPOL systems). This means no wasted traffic capacity. During a transition period, a user can run its analog system and its new TETRAPOL system in parallel on the same repeater sites GMSK modulation with BT = 0,25· Constant envelop Power in adjacent 12.5 kHz channel: - 60 dBc (-70 dBc in an adjacent 25 kHz channel) Compliance with European ETSI standard ETS 300 113