5 Interoperability Methods (Continued) P25 Standards Will FixCommon Air InterfaceModulation SchemesConventional radiosDigital radiosTrunked radiosInternet connectivity (Phase 2)Data Transfer (limited)Narrowband RequirementsWill NOT FixDifferent FrequencyLack of Coverage
6 Urban Area’s Specific Interoperability Technologies Switch to the Statewide Communications Interoperability Plan (SCIP) / Tactical Interoperable Communications Plan (TIC Plan) Informational handout
8 Deployment Considerations PortablePortableFixedTransportableIncident Area Network (IAN) – Small, temporary network created for a specific incidentIncident Area Network (IAN) – Small, temporary network created for a specific incidentJurisdiction Area Network (JAN) - Main communications network for first responders; provides connectivity to the Extended Area Network (EAN).Extended Area Network (EAN) - Links city, county, regional, state, and national systems
9 Deployment Considerations PSTNRemote SitesInterface DevicesCellularVHFNetworkUHF700/800MHzIridium802.XLANAudioGatewayNote:The Audio Bridge/Gateway doesn’t transmit or receive any signals. All modulation and demodulation is accomplished by the interfaced devices.
10 Deployment Considerations: Gateway Placement SmartNetGATEWAYGood SignalConventionalEDACSOut of Range
11 Deployment Considerations: Extending Coverage Area Gateways interfaced to radios using simplex/direct frequencies requires a smaller coverage area and can work well for Incident Area NetworksGateway
12 Activation/De-activation Switch back to the SCIP/TIC Plan Informational handout
13 Gateway Limitations: Overview Gateways retransmit across multiple frequency bands and/or systems providing an interim interoperability solution as agencies move toward shared systems. However, gateways have the following limitations:No EncryptionInefficienciesGeographic AreaPortable Battery LifeSet-up TimeFrequency conflicts/interference
14 Gateway Limitation: No Encryption The Gateways don’t transmit or receive any signalsGateways pass baseband audio (audible voice)All modulation / demodulation and Encryption/Decryption is accomplished by the interface devicesExample: An encrypted signal comes into an interface device, it decrypts the signal and passes the baseband audio to the devices patched to it. If the other devices are encrypted the audio is re-encrypted and sent out. However, if a device isn’t encrypted the audio is still retransmitted in the clear. Remember, at a minimum the audio can be monitored in the clear at the gateway.
15 Gateway Limitation: Inefficiency Additional AssetsTo provide interoperability on the scene of an incident each agency needs to provide a mobile radio in advance or a portable on the scene of the incidentThis ties up one radio asset for each system/channel, the more channels you tie together in a talk group the more radio spectrum being utilizedExample: If we share a common frequency and everyone turns to that frequency we have interoperability, no extra radios or radio frequencies are being used. If we are patched through a gateway, we are still using our radios on the scene but now there are two extra radio assets patched through the gateway and we are using twice the radio spectrum.
16 Gateway Limitation: Coverage Area Gateway's effective geographic coverage area is limited to the area that is common to all systems participating in that link.CommonAreaNote: In this usage the Gateway does not increase your coverage range. Your radio must be able to hit your normal network to communicate
17 Gateway Limitation: Set-Up Some gateways require significant time to configure, others are a matter of simply hooking up radios and turning the system on.It doesn’t matter the type of gateway you use, it is imperative the gateway be configured in it’s standard operating configuration prior to deploymentExample: The gateway will be used to connect an 800 MHz trunked system to a conventional system on a regular basis. The trunk channel requires time to get an acknowledgement tone back from the system prior to transmission; the gateway must be configured to allow for this delay so none of the message is lost during transition. All gateways must pass the shoot/don’t shoot rule losing one word can ruin someone’s day.
18 Gateway Limitation: Battery Life Portable Radios have a Limited Use Time Due to Battery LifeMobile gateways are designed to enable interoperable communications for short duration eventsTo extend mobile gateway operating time, consider: additional power sources, radio chargers, and extra batteries
19 Gateway Limitation: Frequency Conflicts / Interference Antennas must be properly positioned to prevent radio interference or desensitizing the radio receiversIn regions where multiple mobile gateway devices are accessible, it is critical to coordinate the use of these devices to ensure that multiple gateways do not “step-on” each otherExample1: Patching multiple VHF channels on the same Gateway (GW) can raise the noise level in the immediate area of the GW so the effective range may be reduced.Example 2: If GW 1 has 12 radios interfaced to it and the radios are programmed to frequencies GW2 has 5 radios interfaced to it and they are programmed to frequencies GW1 creates a patch between 1, 6, and 8. GW2 creates a patch to 1, 3, and 5. This is the same as if you had one GW patching channels 1, 3, 5, 6 and 8 together. At best this scenario will add confusion, at worst the radio chatter will make both systems unusable. Coordinate all patches through the Incident Communications Leader (COML).
20 Best Practices No Encryption Treat all conversations as if they are in the cleanInefficienciesTo prevent excess chatter, only patch those systems that really need to talk to each other for the time they need to talk. Remember, just because you can patch someone doesn’t mean you shouldNever patch talkgroups on the same trunked system together; you could cause your own system busy.When using an audio gateway with a trunked system, it’s best to have a high priority talkgroup on the system dedicated for gateway use
21 Best Practices (Continued) Geographic AreaUse simplex/direct frequencies for localized incidentsPortable Battery LifeUse mobile radios whenever possibleSet-up TimeInterface radios should be tested and adjusted with the audio gateway prior to initial deployment. Some mobile radios require special programming, others may require hardware modification
22 Best Practices (Continued) Setup Time (Continued)All gateways require special interface cables to connect to the various types of radios. If a radio must be added ad hoc, the requesting organization should provide a portable radio, additional batteries, charger, and the interface cableFrequency conflicts/interferenceCoordination is the key - always go through the Communications Leader prior to creating a patch and know what is being patch