ASTRO 25. Base Station Identification. Receive Implementation Guide

Transcription

1 ASTRO 25 Base Station Identification Receive Implementation Guide Version 1.0 Revision Date: 2 March 2015

2 Change History Issue Date Author Description Jan 2015 CPGR17 Initial Draft Jan 2015 CPGR17 Update following legal review Jan 2015 CPGR17 Updated following FTR Mar 2015 CPGR17 Approved for external distribution Table of contents 1.1 Purpose No Warranty Definitions & Acronyms Background Description of Operation Traffic Channel Identification Control Channel Identification Message Length and Proprietary MAC messages Message Details MOT_BSI_GRANT TSBK used for control channel identification LC_MOT_BSI LC used for FDMA/IVD traffic channel identification MAC_MOT_BSI MAC message used for TDMA/EID traffic channel identification... 8 Page 2 of 8

3 1.1 Purpose This document provides information to manufacturers of APCO Project 25 test equipment to enable implementation of software to decode the base station identification text string which is transmitted using digital messages from Motorola Solutions (referred to as Motorola) ASTRO25 radio sites. Additionally, this document is available for use by Motorola ASTRO25 system owners to comply with 47CFR (f)(2) when using digital only base station ID. 47CFR (f)(2) states: A licensee that identifies its call sign in this [digital] manner must provide the Commission, upon request, information sufficient to decode the digital transmission and ascertain the call sign transmitted. 1.2 No Warranty This information is provided by Motorola Solutions as is and without warranty of any kind, express or implied, including any implied warranty of merchantability, fitness for a particular purpose or non infringement. The information contained in this document is available to anyone wishing to implement the functions described herein, and is subject to change without notice. 1.3 Definitions & Acronyms APCO Association of Public Safety Communications Officials ASCII American Standard Code for Information Exchange BSI Base Station Identification EID Enhanced Integrated Data FACCH Fast Associated Control Channel (for traffic channel pre/post call signaling) FCC Federal Communication Commission FDMA Frequency Division Multiple Access IVD Integrated Voice and Data LB Last Block LC Link Control MAC Media Access Control MCO MAC opcode MFID Manufacturer Identification PDU Protocol Data Unit RF Radio Frequency SACCH Slow Associated Control Channel (for within active traffic channel signaling) TDMA Time Division Multiple Access TSBK Trunked Signaling Block Page 3 of 8

4 1.4 Background The FCC rules regarding station identification were amended in 2013 to allow land mobile stations that are exclusively licensed in the 150 to 512 MHz frequency range to be identified via digital transmission of the assigned FCC callsign. Per (f)(2), Morse code or voice identification is no longer the only option for station identification in this frequency range. Stations licensed on an exclusive basis in the bands between 150 and 512 MHz that normally employ digital signals for the transmission of data, text, control codes, or digitized voice may be identified by digital transmission of the call sign. Prior to this 2013 rule change, only 800 and 900 MHz stations could be identified via digital transmission of the callsign per (c). 1.5 Description of Operation Operation is defined for both traffic and control channel identification Traffic Channel Identification Digital BSI will be sent as a proprietary single Link Control message (FDMA and Integrated Voice and Data traffic channels) or proprietary Media Access Control (TDMA and Enhanced Integrated Data traffic channels) message when assigned for voice/data at the start of the call. Additionally the messages may be sent periodically during transmissions. This operation will be seen on Motorola ASTRO25 systems starting with the 7.16 (Fall of 2015) system release Control Channel Identification Digital BSI is sent periodically as a Motorola proprietary single block Trunked Signaling Block (TSBK) message on each active control channel. This operation will be observed in all current and previous versions of the Motorola ASTRO25 system. Page 4 of 8

5 1.6 Message Length and Proprietary MAC messages Similar to the situation seen for P25 standard MAC messages (discussed in section 8.3 of TIA 102.BBAC), a receiving device needs to be aware of the length of unknown messages so that they can be skipped and later, known proprietary MAC messages in a PDU can be decoded. To allow subscribers to process other messages in the PDU after they encounter an unknown Motorola proprietary message, Motorola proprietary MAC messages added after release one will contain a message length. These are the only two release one MFID $90 proprietary MAC messages (from section 6.2 of TIA 102.AABH) where the length is not contained in b4 b0 of octet 2. The opcodes and lengths of these MFID $90 MAC messages must be known by the receiving device so that later messages can be properly decoded if they are encountered in a PDU. All other MFID $90 MAC messages will contain the length field in octet two. Per TIA 102.BBAC section 8.3, Motorola Solutions ASTRO25 systems comply with the following statement: Any manufacturer specific messages shall be inserted after the standard defined messages and before the null information message since an SU may not be able to decode the length of a manufacturer specific message. Page 5 of 8

6 1.7 Message Details MOT_BSI_GRANT TSBK used for control channel identification Page 6 of 8

7 1.7.2 LC_MOT_BSI LC used for FDMA/IVD traffic channel identification Page 7 of 8

8 1.7.3 MAC_MOT_BSI MAC message used for TDMA/EID traffic channel identification Note: When these messages are used on an EID channel, they will be transported in MAC_IDLE PDUs in the SACCH. They will not be present in the FACCH. When these messages are used on a TDMA channel, they will be transported in MAC_ACTIVE and MAC_HANGTIME PDUs in the SACCH and in the FACCH. Page 8 of 8