![tetrapol scc tetrapol scc](https://careersdocbox.com/docs-images/73/68528506/images/33-0.jpg)
It has two bytes FCS check at the end of structure to check the bits error. In the LLC (Link Level Control) layer, the transmis-sion function is based on high-level data link con-trol (HDLC) procedures which has basic format as Fig. Generally, the frame is obtained by several steps: Discriminator with CRC, Channel encoding, Inter-leaving, Scrambling with formatting, Differential with encoding and Modulation as in Fig. Additionally, Direct Mode Emergency Frame can also be found in the Direct Mode. All these channel frames can be coded in 5 differ-ent types in the Network Mode: Voice, Data, Random Access Frames, Training Frame and SCH/TI Frames. Traffic Channel (TCH) contains SCH (Signalling Channel), SCH/TI (Signalling Channel / Transmitter Interruption), and Voice / Data Chan-nel. The Control Channel contains BCH, SDCH (Signalling and Data Channel), DACH (Dynamic random Access Channel), PCH, RCH (Random ac-cess answer Channel) and RACH (Random Access Channel). In CCH, e.g., Paging Channel (PCH) and Broadcast Channel (BCH) frames. Frames are organized in su-perframes, with a 4 seconds period (or 200 frames), which is synchronized by special frames In the Network Mode a base station (BS) trans-mits one Control Channel (CCH) and several Traffic Channels (TCH), which can be in total up to 24 radio channels. Each radio link of a channel is a succes-sion of 160-bit frames transmitted during 20 ms time intervals. The bit rate is 8 kpbs (bit per second) as well. TETRAPOL uses the GMSK (Gaussian Minimum Shift Keying) modulation scheme at the symbol rate 8 kBd. The channel bandwidth is 5 MHz with channel spacing of 10 kHz or 12.5 kHz. TETRAPOL chooses the FDMA (Frequency Division Multiple Access) as channel access method. In the TETRAPOL Physical Layer, systems may op-erate at radio frequencies of 70 MHz to 520 MHz both in VHF (Very High Frequency) and UHF (Ultra High Frequency) versions. Link Level Control (LLC) + Medium Access Control (MAC) (Layer 2) and They include:Ĭall Control (CC), Mobility Management (MM) and Data Application layers (Layer 4)
![tetrapol scc tetrapol scc](https://ars.els-cdn.com/content/image/3-s2.0-B9781785480225500054-f05-04-9781785480225.jpg)
The TETRAPOL radio protocol layers are shown in Fig.
#TETRAPOL SCC PROFESSIONAL#
TETRAPOL Digital Professional Mobile Radio The mobile stations can communicate in a longer distance than in direct mode. It does not have any co-ordination func-tions. The communication run through a repeater, which just relays the sig-nal. Work also in area where the base station can not cover, e.g., in a tunnel or basement of a building. In this mode two or more mo-bile stations communicate to each other di-rectly, without the co-ordination by a base station. The commu-nication between two mobile stations (MS) always run through the base station (BS).ĭirect mode. In this mode, the terminals connect to a base station (a fixed infrastruc-ture) and are controlled by this. The TETRAPOL system works in mainly three differ-ent modes: The Publicly Available Standard (PAS), which de-fines the various interfaces in a TETRAPOL infra-structure, can be downloaded by registered users. TETRAPOL Forum (provides a collection of manufacturers of TETRAPOL products. Currently, TETRAPOL is proven around the world with 85 networks in around 30 countries. However, TETRAPOL provides a secure and robust voice and data communication in critical situations. Different to the mobile cell phone, the number of participants of a digital trunked communication system (as TETRAPOL) is limited. The main users of the trunked communication system are closed user groups, such as transport services (taxi, state railway and local transport companies),Īirports, energy companies and public security agencies (as police, fire brigade, rescue forces, ar-my, civil protection and boarder control etc.). Today the TETRAPOL technology is supported and further de-veloped by two organizations: by TETRAPOL-Forum (mainly manufacturer) and Users club. The first users of TETRAPOL were the Gendarmerie (mid 1992) and then the police (early 1995) in France. TETRAPOL was developed by Matra Communica-tion (today AIRBUS), France. TETRAPOL offers voice and data services for the most demanding users and professional organizations for mission-critical communications.
![tetrapol scc tetrapol scc](https://1.bp.blogspot.com/-JIpK_Hk8cq0/Whga40B6-fI/AAAAAAAAtz8/rpEgQxjeHg0ytFOuW3G2oqVQO7hrT03sQCLcBGAs/s1600/InmarsatD%2B_1.jpg)
TETRAPOL is a digital trunked mobile radio stand-ard, using an open, digital, purpose-built PMR (professional mobile radio) technology for mission-critical public safety users.