0NXDNTM Specification Overview Level 1 Version 1.2Issued : January 19, 2012JVC KENWOOD CorporationIcom IncorporatedNote : NXDN is the trademark of JVC KENWOOD Corporation and Icom Incorporated.
11. Contents 1. Contents 2. Purpose 3. Copyright and Intellectual Property4. Use Disclaimer5. Scope of this Document6. Items Discussed7. NXDNTM Compliance Certification8. Revision Record for this DocumentP.1P.2P.3P.4P.5P.6 ～35P.36P.37
22. PurposeThis document provides a brief overview of the NXDNTM common air interface protocol and call features related to the supporting IP network systems which are shared under a technology and cooperative development agreement between JVC KENWOOD Corporation and Icom Incorporated.The contents of this document are disclosed without limitation for the purpose of expanding NXDNTM with interested parties.
33. Copyright and Intellectual Property This document and its contents are copyright protected and are the property of JVC KENWOOD Corporation and Icom Incorporated.Certain technologies discussed in this document are the intellectual property of JVC KENWOOD Corporation and/or Icom Incorporated.Use of any intellectual property contained in this document is not permitted unless authorized by JVC KENWOOD Corporation or Icom Incorporated.
44. Use DisclaimerAlterations or deletions of any item in this document may be done without obligation of any prior notice provided no agreement to the contrary exists between JVC KENWOOD Corporation and Icom Incorporated and the party this document is disclosed to.If the receiving party sustains tangible or intangible damages from the use or consideration of use of the contents, including any subsequent alterations or deletions, neither JVC KENWOOD Corporation or Icom Incorporated shall be held liable and accountable for any compensation for said damages.
55. Scope of this DocumentA brief overview of the specifications pertaining to:a) Wireless communication systems for the Americas’ private landmobile markets in the VHF, UHF and 800MHz frequency bands and,b) the FDMA method for 6.25kHz or 12.5kHz bandwidth and,c) the system using this communication protocol
66. Items Discussed The following items are specified in this document. 6-1 Defined ServicesVoice Call Services (Group, Individual, etc.)Data Call Services (Long Data, Short Data, etc.)Supplemental Services (Status Call, Emergency, Encryption, etc.)Trunked System Services (Registration, Roaming, etc.)6-2 Conventional System6-3 Trunked System6-4 Channel Parameters6-5 Vocoder6-6 Concept of Channel Definition (Conv. & Type-C)Frame Structure ConceptVoice Frame Structure (Conv. & Type-C)Data Frame Structure (Conv. & Type-C)Control Channel Frame Structure (Type-C)Random Access on Control Channel (Type-C)Link Time of Group Call (Type-C)6-7 Concept of Channel Definition (Type-D)Voice Frame Structure (Type-D)Data Frame Structure (Type-D)Link Establishment Frame Structure (Type-D)Link Time of Group Call on Home Repeater (Type-D)"Conv.": Conventional"Type-C": Type-C Trunking"Type-D": Type-D Trunking
76-1-1. Defined Services in Conventional System Directvia RepeaterVoice ServiceUnaddressed Voice Call (using RAN)MandatoryGroup Voice CallStd. OptionIndividual Voice CallInterconnect Voice Calln/aData ServiceData Call (Group, Individual)Short Data Call (on Control Channel)Simultaneous Data CallSupplementaryStatus CallEmergency Call & AlertRemote Control (Stun, etc.)ESN ValidationLate EntryEncryptionMandatory : Mandatory Service Std. Option : Standard Option Service
86-1-2. Defined Services in Trunked System Type-CType-DMulti SiteSingle SiteVoice ServiceGroup Voice CallMandatoryIndividual Voice CallInterconnect Voice CallStd. OptionData ServiceData Call (Group, Individual)Short Data Call (on Control Channel)n/aSimultaneous Data CallSupplementaryStatus CallEmergency Call & AlertRemote Control (Stun, etc.)ESN ValidationLate EntryEncryptionSystem ServiceRegistrationRoamingOver the Air UpdateAuthenticationComposite Control CHCall Queuing2nd Home RepeaterPriority MonitorFailsoftMandatory : Mandatory Service Std. Option : Standard Option Service
9Voice Call ServicesUnaddressed Voice Call (RAN Only) A Subscriber Unit (SU) or console can provide a Voice Call intended for calls to Subscriber Units with same RAN (Radio Access Number), without using any identifier for selective call.Group Voice CallA Subscriber Unit (SU) or console can provide a Group Voice Call intended for calls to multiple Subscriber Units. According to group settings, this can provide a Conference Call for two-way voice calls between selected groups or a Broadcast Call for one-way voice calls to the selected Group.Individual Voice CallA Subscriber Unit (SU) or console can provide an Individual Voice Call intended for calls to a specified Subscriber Unit.Interconnect CallTrunking Repeater Sites (TRS) or Conventional Repeater Sites (CRS) can be connected to telecommunication networks (PSTN/ PSDN), which can offer individual or group voice calls between Subscriber Units and the PSTN/PSDN.
106-1-4. Data Call Services Data Call A Subscriber Unit (SU) or console can transfer data (e.g. text, or AVL data) to an individual or group members. A Data Call can be sent to one specified Subscriber Unit or a Broadcast Data Call to a group can be selected.Short Data CallA Subscriber Unit (SU) or console can transfer a small amount of data to individual or group members. The size of transmission data has a limit because the control channel of a Trunking Repeater Site (TRS) is used. A Short Data Call can be sent to one specified Subscriber Unit or a Broadcast Short Data Call to a group can be selected.Simultaneous Data CallA Subscriber Unit (SU) or console can transfer data at a low speed simultaneously with a voice call during Individual Voice Calls or group voice calls. This function enables data transmission similar to a Short Data call during a voice call.
116-1-5. Supplementary Services (1) Status Call (Status Notice and Status Inquiry)A Subscriber Unit (SU) or console can transfer a simple and fixed message to individual or group members. There are 2 types of usages: preconfigured particular status messages and user defined free-style status messages. Also, there are two methods to send or get a status: Status Notice is a function that an SU sends a status message as necessary, and Status Inquiry is that an SU sends a status message when it receives an inquiry command message.Emergency Call & AlertWhen a Subscriber Unit (SU) is in emergency condition, an emergency voice call or emergency status message can be sent to an individual or group members.Remote Control (Stun/Revival/Kill, Monitor)A Subscriber Unit (SU) or console can set a specified Subscriber Unit to an inoperative state remotely. There are three kinds of states, Stun, Revival, and Kill, and a Subscriber Unit or console can initiate any of these if enabled. Furthermore, an SU or console can let a specified Subscriber Unit transmit remotely (Remote Monitor).
126-1-6. Supplementary Services (2) ESN ValidationEach Subscriber Unit (SU) has a unique Electronic Serial Number (ESN) that is written in its memory device at a factory. A validation facility such as a console can authorize an SU using ESN and prevent unauthorized usage of the system.Late EntryLate Entry enables those Subscriber Units that access a call after a group call is established to automatically join the group call. This scenario could occur when a Subscriber Unit enters the region from outside the coverage area, or if a Subscriber Unit is turned ON after a group call is established.EncryptionContents of voice communication and data communication may be encrypted. Three encryption modes are available; Scramble Mode (15-bit key), DES Mode (56-bit key) and AES Mode (256-bit key).
136-1-7. Trunked System Services (1) RegistrationIn a Trunked Radio System, a Subscriber Unit searches for another control channel when the unit is turned ON, or if the receive signal becomes low in standby mode, to select another Trunking Repeater Site with better signal conditions and the Unit ID may be registered in the new Trunking Repeater Site.RoamingIn a Trunked Radio System that has multiple Trunking Repeater Sites (TRS), the location registration is updated and traced in Trunking Repeater Sites when a Subscriber Unit moves around sites. Trunking Repeater Sites broadcast the neighboring site information to transfer the Subscriber Units appropriately.Over the Air UpdateIn Trunked Radio System, Trunking Repeater Sites (TRS) can inform SU over the air, when a new site is added.
146-1-8. Trunked System Services (2) AuthenticationUsing a unique Electronic Serial Number (ESN) given to each Subscriber Unit, a Trunking Repeater Site can authorize a Subscriber Unit and prevent unauthorized usage of the system.Composite Control ChannelAt a Trunking Repeater Site, if a new transmission request is placed when all traffic channels in the site are busy, a control channel may be assigned temporarily as a traffic channel to enable communication.Call QueuingAt a Trunking Repeater Site, if an SU sends a new call request when all traffic channels in the site are busy, the TRS sets the SU queuing state and may keep the SU waiting until the call request is processed.
156-1-9. Trunked System Services (3) Secondary Home RepeaterIn a Trunked Radio System, SU registers the Trunked Repeater (TR) called Home Repeater. If the line control of the TR becomes inoperative because of some trouble, another TR becomes Secondary Home Repeater which performs line control temporarily.Priority MonitorIn the state where an SU is making a group call on a traffic channel, when a priority Group Call begins on other traffic channel or a call request of Individual Call addressing the SU occurs, the SU drops out of the Group Call and can participate in the priority Group Call or the Individual Call.FailsoftIf a Trunking Repeater Site (TRS) fails and loses its channel control, the TRS behaves equivalent to a conventional repeater by repeating the received signal so that it provides minimum service to SUs and allows communications between SUs within the service area.
166-2. Conventional System16 bit Unit ID, uniquely definable for each systemIdentifiable approx. 65,000 units per system16 bit Group ID, uniquely definable for each systemIdentifiable approx. 65,000 groups per system6 bit Radio Access Number (RAN)CTCSS/CDCSS like operationSimilar operation to an analog system possibleGroup call using only RAN (CTCSS/CDCSS like)Selective call using RAN and Unit/Group ID (CTCSS + DTMF like)Even if in Selective Call, Late Entry function works properlyCommunity Repeater operation with RAN4800bps/6.25kHz and 9600bps/12.5kHz available
17Trunked SystemTwo types of trunked system Type-C; Centralized control method with the dedicated control channel Type-D; Distributed control method without the dedicated control channelSystem ConfigurationSupport Multi Site ConfigurationSupport Multi System Configuration
186-3-2. Type-C Trunked System FeaturesUsing a dedicated control channel transmitting continuously,Suitable for the sites with many channels and the systems with many sitesEfficient packet switched data modeRapid control channel hunting and site roamingExclusive channel license necessarySystem Identification24-bit Location ID for identifying each system and each site6-bit Site Code for identifying each siteSubscriber Identification16-bit Unit ID --- Identifiable approx. 65,000 units per system16-bit Group ID --- Identifiable approx. 65,000 groups per systemAvailable Mode4800bps/6.25kHz and 9600bps/12.5kHz available
196-3-3. Type-D Trunked System FeaturesAll of channels available as traffic channelEfficient channel use in a small number of channelsLess channel interferenceShared channel license availableSystem Identification19-bit System ID for identifying each system8-bit Site Code for identifying each siteHome Repeater & Subscriber Identification5-bit Home Repeater/Prefix for identifying each sub-group11-bit Unit ID --- Identifiable approx. 2,000 units per prefix11-bit Group ID --- Identifiable approx. 2,000 groups per prefixAvailable Mode4800bps/6.25kHz available
216-5. Vocoder AMBE+2TM from DVSI Inc. 4800bps mode can use only the EHR 3600bps EHR (Enhanced Half Rate)Voice; 2450bps, FEC; 1150bps7200bps EFR (Enhanced Full Rate)Voice; 4400bps, FEC; 2800bps4800bps mode can use only the EHR9600bps mode can use the EHR or optional EFRP25 Vocoder CompatibilityP25 Phase 1 uses 7200bps IMBETM which is has less quality than EFREFR has a backward compatibility to IMBETM
226-6-1. Concept of Channel Definition Conv. & Type-C3 Physical Channels (same meaning as “Carrier” or “Frequency”)RCCH (RF Control Channel for Type-C Trunking)RTCH (RF Traffic Channel for Type-C Trunking)RDCH (RF Direct Channel for Conventional)9 Functional Channels (transferred information dependent)VCH (Voice Channel for Vocoder data)SACCH (Slow Associated Control Channel)FACCH1 (Fast Associated Control Channel 1)UDCH (User Data Channel)FACCH2 (Fast Associated Control Channel 2)BCCH (Broadcast Control Channel)CCCH (Common Control Channel)UPCH (User Packet Channel)LICH (Link Information Channel)5 functional channels for RTCH and RDCH3 functional channels for RCCH1 common functional channel
236-6-2. Frame Structure Concept Common384 bits2016348FSWLICHdifferent usage every mode (voice, data, …)2016348FSWLICHdifferent usage every mode (voice, data, …)4800bps and 9600bps modes have the same frame structureOne frame always has a 384 bit length regardless of the modes4800bps: 384 bits / 4800 bps = 80 ms frame length9600bps: 384 bits / 9600 bps = 40 ms frame lengthFSW (Frame Sync Word) and LICH in the head of frameFSW is the fixed 20 bit pattern for synchronizationLICH indicates the kind of radio channel and functional channelSubscriber determines the area following LICH by decoding LICH
246-6-3. Voice Frame Structure in 4800bps Conv. & Type-C384 bits72166020Voice OnlyFSWLICHSACCHVCHStealingData with VoiceFSWLICHSACCHFACCH1VCHRTCH (trunk) and RDCH (conv.) have the same frame structureAMBE+2TM converts each 20ms voice signal to digitized data3600bps x 20ms = 72bit, 4 VCH are included in 80ms frameUsing “steal”; 2 VCH change to FACCH1, simultaneous Data w/Voice function is availableSACCH always attaches VCH for sending the control dataGroup/Unit ID and many kind of control informationFACCH1 is used for Simultaneous Data (Data w/Voice) and Status Call and many kinds of control messages
256-6-4. Voice Frame Structure in 9600bps Conv. & Type-C40ms, half the 4800bps modeFSWLICHSACCHVCH7216602080ms, 384 bitsFACCH1residual time of 40msgives more functionalityCompatible frame structure with 4800bps, less design complexityIn 9600bps mode, more flexible operation is availableUsing FACCH1, faster Data w/ Voice with no voice quality degradationUsing EFR Vocoder, higher voice quality is availableIf FACCH1 is not needed, intermittent Tx and Rx allows for longer battery Life
266-6-5. Data Frame Structure Conv. & Type-CFSWLICHUDCH or FACCH23481620384 bitsData frame sends user data (e.g. text, AVL, image data, etc)In a Long Data Call, user data is divided into many packets, and each packet is divided into blocks again, then one block is carried by one UDCH.FACCH2 is used for Status Call and some control messages
276-6-6. Control Channel Frame Structure Type-C384 bits201625296FSWLICHCAC (CCCH or UPCH)GuardInbound20163002424OutboundFSWLICHCAC (BCCH or CCCH or UPCH)EPostInbound frame has a 96 bit guard time not to transmitGuard time is or This timing does not require the severe ramping time for TX APC circuitryOutbound frame has an E field and a Post fieldE (collision control) field is for random access controlPost field is for faster frame synchronization
286-6-7. Random Access on Control Channel in 4800bps Type-COutboundCCCHCCCHCCCHCCCHCCCH80msInboundUnit #1CCCHCCCHUnit #240ms offset20ms guard timeOne random access slot identifies one frameSubscriber transmits at 40ms offset to outbound frameTypically the subscriber sends one message using one slotRegistration, Call request, Status, etcWhen sending Short Data, the subscriber can use plural slotsCCCH for a single message, UPCH for plural messages
296-6-8. Link Time of Group Call in 4800bps Type-CCCCH80msOutbound RCCHCCCHREQ40msASSGNCCCHRX40msCCCHVoiceInbound RCCHInbound RTCH320ms typicallyPTTGroup Call Sequence (E field handling is omitted)User presses the PTT, thenSubscriber sends Call Request using random access on RCCH, thenController assigns RTCH and Subscriber receives RTCH ASSIGN, thenSubscriber moves to the assigned RTCH and starts transmission, thenUser hears the Proceed Tone and begins to talkTypical Link Time is 320 ms in 4800 bps (similar to LTR system)
306-6-9. Link Time of Group Call in 9600bps Type-COutbound RCCHCCCHCCCHCCCHCCCHASSGNCCCHCCCHInbound RCCH40msREQRXInbound RTCHVoice220ms typicallyPTTTypical Link Time is 220 ms in 9600 bpsCall sequence is the same as that of 4800bpsInbound frame offset is 0 msHowever Tx <-> Rx switching time are still 40msThis link time is one of the shortest Link Time in LMR systems
316-7-1. Concept of Channel Definition Type-D1 Physical Channels (same meaning as “Carrier” or “Frequency”)RTCH2 (RF Traffic Channel 2)6 Functional Channels (transferred information dependent)VCH (Voice Channel for Vocoder data)SCCH (Signaling Control Channel)FACCH1 (Fast Associated Control Channel 1)UDCH2 (User Data Channel 2)FACCH3 (Fast Associated Control Channel 3)LICH (Link Information Channel)6 functional channels for RTCH2
326-7-2. Voice Frame Structure Type-D384 bits72166020Voice OnlyFSWLICHSCCHVCHStealingData with VoiceFSWLICHSCCHFACCH1VCHRTCH2 have the same frame structure as RTCH/RDCH except SCCHUsing “steal”; 2 VCH change to FACCH1, simultaneous Data w/Voice function is availableSCCH always attaches VCH for sending the control dataGroup/Unit ID and many kind of control informationFACCH1 is used for Simultaneous Data (Data w/Voice) and Status Call and many kinds of control messages
336-7-3. Data Frame Structure Type-D384 bits288166020FSWLICHSCCHUDCH2 or FACCH3Data frame sends user data (e.g. text, AVL, image data, etc)In a Long Data Call, user data is divided into many packets and each packet is divided into blocks again, then one block is carried by one UDCH2.FACCH3 is used for Status Call and some control messages
346-7-4. Link Establishment Frame Structure Type-D384 bits144166020InboundFSWLICHSCCHFACCH1Guard14412016602024OutboundFSWLICHSCCHFACCH1NPostFrames during link establishment are similar to the frame structure of Voice FrameInbound frame has a 144 bit guard time not to transmitOutbound frame has a Null field and a Post fieldE (collision control) field is for random access controlPost field is for faster frame synchronization
356-7-5. Link Time of Group Call on Home Repeater Type-D50msRXPTT70msVoice400ms typically80msREQRESPNOutboundInboundGroup Call SequenceUser presses the PTT, thenSubscriber sends Call Request using random access, thenSubscriber receives Call Response from Home Repeater indicating receive success, thenSubscriber starts transmission on Home Repeater, thenUser hears the Proceed Tone and begins to talkTypical Link Time is 400 ms (similar to LTR system)
367. NXDNTM Compliance Certification Compliance Certification for NXDNTM compatible products produced and/or sold by NXDN Forum members are defined as follows;1) Developers must apply to Technical Working Group according tothe NXDNTM Compliance Certification Procedure document provided tothe Forum members.2) Compliance Certification includes application examination,conformance tests and other requirements.3) The use of the NXDNTM logo mark is permitted upon successfulcompletion of the Compliance Certification.
378. Revision Record for this Document August 3, Version 1.0February 5, 2008 Version 1.1January 19, 2012 Version 1.2