Technical Background. All TG names programmed in the County’s 800MHz Trunked Radio System must be unique and consistent from Zone Manager to subscriber. Due to the fact that the newer subscriber units will have a maximum of twelve (12) characters on their display, TG length will be limited to a maximum of twelve (12) characters. When possible, subscriber TG will be consistent with the console database and zone controller. Any subscriber with less than eight (8) characters display will be handled on a case by case basis.
Technical Background. Capabilities The “Emergency Button” feature, if it is programmed into the subscribing agency radios, will allow a radio user to send an emergency notification by pressing the specific Emergency Button on the radio. The notifications will audibly and visually alert all dispatch console positions that have the talk group up that the emergency notification is routed to. Other radios that have the talk group selected will also receive the emergency notification, and display the radio ID of the radio generating the emergency. The display of an ID is dependent upon radio model, firmware version, and purchased options. The user activating the Emergency Button has the obligation to properly cancel the activation by pushing – and holding the Emergency Button until a continuous tone sounds. Failure to properly cancel the alarm on the originating radio will cause a new alarm activation each time the user transmits. Emergency calls are also automatically assigned the highest priority available and would be the first available from the queue if the system is in a busy situation. Subscriber’s radios can optionally be configured to automatically activate the Push-to-Talk (PTT) for a programmed period of time if the Emergency Button is pressed. Constraints Consider two situations a fire department engine company could be faced with, that show different operational needs:
Technical Background. Constraints Radios must meet the recommended standards as set forth when auxiliary equipment is needed by the individual radio subscriber to perform their job. These standards identify the proper radio auxiliary equipment to be used in conjunction with the radio subscriber’s model type.
Technical Background. Constraints Radios must meet the recommended standards as set forth. These standards identify the proper radio to be used in conjunction with the required features and auxiliary equipment (to be described in Section 1.7) Each subscriber radio will be assigned it’s unique Radio ID number, Alias Name and programmed with a codeplug/template that has been approved by the user’s upper level management.
Technical Background. Capabilities Interconnect calls can be placed to individual users of the system, if they are configured for interconnect functionality. Interconnect calls can be placed to talk groups of the system, if the Talk Group is configured for interconnect functionality. Constraints o An interconnect call will consume an RF channel for the duration of the call. o Interconnect calls are half duplex; only one end can talk at a time. o A type 1 portable cannot initiate an interconnect call. o A type 2 portable can only place calls to numbers that are pre-programmed into the radio. o A type 3 portable can place an interconnect call by dialing the number directly. o The general public can easily monitor the interconnect calls and they are NOT private or protected in any way. o Interconnect shall NOT be utilized to conduct confidential business such as discussing case strategy with the State Attorney’s Office.
Technical Background. Capabilities The network infrastructure and subscriber units need to be configured to permit managed user Scanning of Talk Groups. Whether or not Scanning will be utilized in subscriber radios, it is at the option of the user agency. Users also need to be trained that merely including a Talk Group in a non-priority Scan list will not necessarily result in the user hearing traffic on that Talk Group. The Talk Group must also be “active” at the site where the user is affiliated. Talk Groups are active on a site if the Zone Controller is programmed to allow the Talk Group to appear on that site and there is at least one user affiliated at the site which has the Talk Group of interest as their selected channel. Constraints How the radio is programmed to handle wide area and local sub-system Talk Groups will determine priority Scan capabilities. If the local sub-system Talk Groups is not programmed to the same “system” in the radio, they cannot be included in the priority monitor Scan list. In this case, only Talk Group Scan can be implemented. Priority Scan requires System Infrastructure configuration in order to perform as expected. The Talk Groups that are deemed to be Priority Monitor Groups need to be configured as such by the System Managers. There are practical limitations on the overall number of Priority Monitor Groups that can be enabled due to the amount of time required to distribute the list of active Talk Groups to the radios in real-time. Talk Group Scan does not provide a priority feature to direct the radio to the priority Talk Group. Talk Group Scan can Scan Talk Groups from different systems (as defined in the radio internal programming) and conventional channels. It is strongly recommended that “talkback Scan” not be used. Talkback Scan would direct the user to transmit on the last active Talk Group the radio heard traffic on. This will cause confusion as the radio user will not know what Talk Group the radio will be transmitting on as it will constantly change based upon what the radio last received. Scan is not recommended for those users that must hear critical communications. While Scanning will be available on the systems it will necessarily be limited and, therefore, not be as robust as in conventional radio systems.
Technical Background. Constraints Every Radio User ID in the system has to be unique; there can be no duplicate IDs. The Radio User Alias field itself will hold up to 14 characters and the legal values that the system will accept are: Upper Case Alpha, Numeric, Period, Dash, Forward slash, Number sign. When agencies make additions, deletions and changes to the database for Radio Aliases the modifications will not take effect until Motorola performs a database back-up that will occur every Friday. The Dispatch consoles will not reflect these modifications until that step is taken.
Technical Background. Capabilities Private calls can be placed to individual users of the system, this communication is outside of the Talk Group communications, and is a private communication between two radio users. Console operators can place private calls to the radio users. Constraints o A private call will consume a RF channel for the duration of the conversation. o Private calls are half-duplex, only one end can talk at a time. o A type 1 portable cannot initiate a private call. o A type 2 portable can only place private calls to numbers that are pre- programmed into the radio. o A type 3 portable can place a private call by dialing the number directly. o Private calls are not recorded. o For the duration that a radio user is involved in a private call, the user will not be involved in dispatch / Talk Group communications. o The system is not able to restrict the usage of private call on the system, unlike interconnect calls, which can be managed.
Technical Background. Audio Logging Recorder allows all voice radio traffic to be recorded and stored for future reference. All Talkgroups are recorded and maintained by LA-RICS for a period of not less than ninety (90) days. A Talkgroup does not need to be selected or active at a console position to be recorded. Advanced Encryption Standard (AES) Encrypted calls are recorded, however, if the encryption key is not installed into the system, those recordings are unusable until the key is provided.
Technical Background. Constraints: The serial number field in Radio ID screens in 12 characters long. Every Talkgroup per console position requires a Radio ID programmed for that position, for example a single console position may have 50 radio ID programmed to support that position.
