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  • Radios

    How many of your depts use mobile (in car) radios as well as portable (on your duty belt) radios? We just have portables but I think having mobiles would also be beneficial (altho expensive)... You guys think mobiles are necessary?
    We have mobile (in car) as well as portable (on your belt) radios.
    We just have portable (on your belt) radios.
    We have both, but I just mainly use my portable even when in the car.
    Last edited by flydream777; 08-27-2008, 01:06 AM. Reason: typo

  • #2
    Originally posted by flydream777 View Post
    How many of your depts use mobile (in car) radios as well as portable (on your duty belt) radios? We just have portables but I think having mobiles would also be beneficial (altho expensive)... You guys think mobiles are necessary?

    We use both. And in some spots they are equally useless.

    But it all depends on square miles and repeaters. If you don't have enough towers/repeaters it doesn't make a bit of diffrence what you're using. (800mhz-900mhz anyway)
    "Why is common sense so rare?" - Me

    By the way.. They aren't "Clients" or "Customers" they're CRIMINALS... sheesh


    • #3
      both and if im in the vehicle i use the in car radio if I step out i use my portable. Were on the digital systems so its rare if we don't get "service" in an area but it does happen occasionally.


      • #4
        We have both, but I doubt the in-car one works. lol So we all just use our shoulder mics.
        The sheep generally do not like the sheepdog. He looks a lot like the wolf. He has fangs and the capacity for violence. The difference, though, is that the sheepdog must not, cannot and will not ever harm the sheep. Any sheepdog who intentionally harms the lowliest little lamb will be punished and removed.

        I Am the Sheepdog.

        "And maybe just remind the few, if ill of us they speak,
        that we are all that stands between
        the monsters and the weak." - Michael Marks



        • #5
          Belt only for us, but we've got good coverage in the vast majority of the county. A few outlying corners don't have a good signal, yet. I've got enough mics in my car without needing another, it would just confuse me...
          I miss you, Dave.


          • #6
            Any one here project 25 compliant?
            It could be that the purpose of your life is only to serve as a warning to others.


            • #7
              We have both. Both the portable and the in car have the capability to scan and talk to other departments.

              We are using 800 radios. Unfortunately the radios are from the Atlanta Olympics which equals used at the time of the Olympics. We are now looking at about 12 years since those games and we are still using the same hardware. There are many problem spots throughout town, especially inside metal buildings.

              It is much better than the old system where in certain parts of town the station could not hear what you were saying even from the cruiser. It was necessary to relay your information through a neighboring town who would then call your department with the information.


              • #8
                Originally posted by DACP View Post
                Any one here project 25 compliant?
                Is that where you can talk to UFOs? If so, my fire chief is. I swear he's got enough radios to talk to the space shuttles, while they're in orbit.
                “We don't disagree, you are wrong. Until you have a clue what you are talking about we can't disagree.” - cgh6366


                • #9
                  We use and need both. There have been occasions where we need to switch to the Metro PD for assistance and it is easier to scroll to the different zone/channel on the car radio. More importantly, the car radio will reach further off the various repeaters.
                  I'm 10-8 like a shark in a sea of crime..


                  • #10
                    Originally posted by nuthead View Post
                    Is that where you can talk to UFOs? If so, my fire chief is. I swear he's got enough radios to talk to the space shuttles, while they're in orbit.
                    from Wikipeda:

                    Project 25 (P25) or APCO-25 refer to a suite of standards for digital radio communications for use by federal, state/province and local public safety agencies in North America to enable them to communicate with other agencies and mutual aid response teams in emergencies. In this regard, P25 fills the same role as the European Tetra protocol, although not interoperable with it.

                    P25 was established to address the need for common digital public safety radio communications standards for First Responders and Homeland Security/Emergency Response professionals. TIA TR-8 facilitates such work through its role as an ANSI-accredited Standards Development Organization (SDO).

                    “ Project 25 (P25) is a set of standards produced through the joint efforts of the Association of Public Safety Communications Officials International (APCO), the National Association of State Telecommunications Directors (NASTD), selected Federal Agencies and the National Communications System (NCS), and standardized under the Telecommunications Industry Association (TIA)... The P25 suite of standards involves digital Land Mobile Radio (LMR) services for local, state/provincial and national (federal) public safety organizations and agencies...
                    P25 is applicable to LMR equipment authorized or licensed, in the U.S., under the National Telecommunications and Information Administration (NTIA) or Federal Communications Commission (FCC) rules and regulations.

                    Although developed primarily for North American public safety services, P25 technology and products are not limited to public safety alone and have also been selected and deployed in other private system application, worldwide.[1]

                    P25 equipment has also been selected for a railroad system, including rolling stock, personnel, and transportation vehicles.[citation needed]

                    P25-compliant systems are being increasingly adopted and deployed. Radios can communicate in analog mode with legacy radios, and in either digital or analog mode with other P25 radios. Additionally, the deployment of P25-compliant systems will allow for a high degree of equipment interoperability and compatibility.

                    P25 standards use the Improved Multiband Excitation (IMBE) vocoders which were designed by DVSI to encode/decode the analog audio signals.

                    P25 may be used in "talk around" mode without any intervening equipment between two radios, in conventional mode where two radios communicate through a repeater or base station without trunking or in a trunked mode where traffic is automatically assigned to one or more voice channels by a Repeater or Base Station.

                    The protocol supports the use of DES encryption (56 bit), 2-key Triple-DES encryption (112 bits), 3-key Triple-DES encryption (168-bits), AES encryption at up to 256 bits keylength, RC4 (40 bits, sold by Motorola as Advanced Digital Privacy), or no encryption.

                    The protocol also supports the ACCORDION 1.3, BATON, FIREFLY, MAYFLY and SAVILLE Type 1 ciphers.

                    P25 Open Interfaces
                    P25's Suite of Standards specify eight open interfaces between the various components of a land mobile radio system. These interfaces are:

                    Common Air Interface (CAI) standard specifies the type and content of signals transmitted by compliant radios. One radio using CAI should be able to communicate with any other CAI radio, regardless of manufacturer
                    Subscriber Data Peripheral Interface standard specifies the port through which mobiles and portables can connect to laptops or data networks
                    Fixed Station Interface standard specifies a set of mandatory messages supporting digital voice, data, encryption and telephone interconnect necessary for communication between a Fixed Station and P25 RF Subsystem
                    Console Subsystem Interface standard specifies the basic messaging to interface a console subsystem to a P25 RF Subsystem
                    Network Management Interface standard specifies a single network management scheme which will allow all network elements of the RF subsystem to be managed
                    Data Network Interface standard specifies the RF Subsystem's connections to computers, data networks, or external data sources
                    Telephone Interconnect Interface standard specifies the interface to Public Switched Telephone Network (PSTN) supporting both analog and ISDN telephone interfaces.
                    Inter RF Subsystem Interface (ISSI) standard specifies the interface between RF subsystems which will allow them to be connected into wide area networks

                    P25 Phases
                    P25-compliant technology is being deployed in several phases:

                    Phase 1
                    Phase 1 radio systems operate in 12.5 kHz analog, digital or mixed mode. Phase 1 radios use Continuous 4 level FM (C4FM) modulation for digital transmissions at 4800 baud and 2 bits per symbol, yielding 9600 bits per second total channel throughput. Receivers designed for the C4FM standard can also demodulate the "Compatible quadrature phase shift keying" (CQPSK) standard, as the parameters of the CQPSK signal were chosen to yield the same signal deviation at symbol time as C4FM while using only 6.25 kHz of bandwidth
                    Vendors are currently shipping Phase 1 P25-compliant systems. These systems involve standardized service and facility specifications, ensuring that any manufacturers' compliant subscriber radio has access to the services described in such specifications. Abilities include backward compatibility and interoperability with other systems, across system boundaries, and regardless of system infrastructure. In addition, the P25 suite of standards provides an open interface to the radio frequency (RF) subsystem to facilitate interlinking of different vendors' systems.

                    Phase 2
                    To improve spectrum utilization, Phase 2 is currently under development with concurrent work being done on 2-slot TDMA and FDMA (CQPSK) modulation schemes. Phase II will use the AMBE vocoder to reduce the needed bitrate so that one channel will only require 4800 bits per second.

                    Significant attention is also paid to interoperability with legacy equipment, interfacing between repeaters and other subsystems, roaming capacity and spectral efficiency/channel reuse. In addition, Phase 2 work involves console interfacing between repeaters and other subsystems, and man-machine interfaces for console operators that would facilitate centralized training, equipment transitions and personnel movement.
                    It could be that the purpose of your life is only to serve as a warning to others.


                    • #11
                      Some would say i'm suicidal for going out without a gun so I wouldn't be that keen to be going out without my lifeline ie a personal radio.

                      Having switched from a combined 150MHz/450MHz VHF/UHF system (that was good in its day [1970's] but rubbish towards the end) and now having gone to one 390MHz Digital system then we have both, mobile 15w radios in the cars and 5w handhelds. I can live without the vehicle set, although its handy to have, wouldn't be going anywhere without my handheld though.

                      Mobiles are good for pursuits (as we have handsfree radios) and more remote areas of poor coverage due to the higher power. As we have national inter service interoperability then it gradually becomes more and more important to you.


                      • #12
                        We have both.


                        • #13
                          I have three different types of mobile radios in my vehicle and two different ones I can wear on my belt.


                          • #14
                            Originally posted by ArkansasFan24 View Post
                            I have three different types of mobile radios in my vehicle and two different ones I can wear on my belt.
                            that is too much. we have one on the belt and one mounted in the car. with both we can contact all our dispatch channels along with the pd's in the county, the sheriff's offices in the surrounding counties, and us forest service. there is also a bunch of mutual aid channels to connect to other agencies around the state.


                            • #15
                              We have both.....we have recently (last 5 years or so) added the capability to talk with LAPD and other agencies on our radios if needed......
                              The posts on this forum by this poster are of his personal opinion, and his personal opinion alone

                              "Politicians are like diapers. They need to be changed often and for the same reason"

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