Ocean Signal AIS Class-B SOTDMA Transceiver CB1, CB2

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Ocean Signal AIS Class-B SOTDMA Transceiver CB1, CB2

Postby jimh » Mon Dec 06, 2021 10:05 am

OCEAN SIGNAL of England has a Class-B Self-organizing Time Domain Multiple Access (SOTDMA) AIS transceiver model ATB1, which is also packaged and sold by ACR as their model AISLINK CB2. Unlike many AIS devices which are manufactured by an OEM for private label branding, the Ocean Signal/ACR device appears to be actually made by Ocean Signal.

Fig. 1. Ocean Signal ATB1 AIS transceiver.
OceanSignalATB1.jpg (26.3 KiB) Viewed 6509 times

Fig. 2. ACR AISLINK CB2 AIS transceiver.
AISLINK_CB2.jpg (26.87 KiB) Viewed 6509 times

As with all AIS devices, two certification hurdles must be passed in order for the AIS device to be sold in the United States. First, the USCG must test and approve the device. The USCG gave approval under their designation 165.156/44/0. The USCG approval tests for compliance with with the following international standards for marine radio devices:
    IMO Resolution A.694(17)
  • IMO Resolution MSC.74(69) Annex 3
  • IEC 60945 (2002) with Corrigendum 1 (2008)
  • IEC 61162 (applicable part)
  • IEC 62287-2 (2017)
  • ITU-R M.1371

The second hurdle is FCC approval. FCC defers actual testing for compliance to recognized testing standard organizations. The ATB1 AIS device was tested by a TÜV SÜD in 2019. The term TÜV in German is Technischer Überwachungsverein , which translates to "Technical Inspection Association." TÜV SÜD prepared a comprehensive report of the test findings, which the FCC then accepts as evidence of the device's compliance with FCC regulations. The testing began in 2017 and was completed in 2019. The FCC has designated these devices under the indentifier XYEATB1. For more details of the FCC certification, you can use their "Authorization Search" webpage and the device ID to locate extensive supporting documentation.

The ACR version model AISLINK CB2 is now available in the USA at a retail price of $800. WEST MARINE is currently selling them.

These Class-B AIS transceivers using SOTDMA are sometimes referred to as "Class-B Plus" or as "Class B+"; they provide advantages over the earlier and more commonly found Class-B AIS transceivers that use Carrier Sense Time Division Multiple Access (CSTDMA) techniques. The advantages of Class-B SOTDMA include:
  • increase in transmitter power output to 5-Watts from 2-Watts resulting in longer range
  • faster reporting rate, as high as every five seconds compared to every 30-seconds
  • assured reservation of transmit time slot to prevent being blocked from transmitting in high-traffic areas

The Ocean Signal ATB1 transceiver includes the following components:
    ATB1 tranceiver
  • mounting screws
  • Power-Data cable assembly
  • USB to Micro-USB cable
  • USB On-the-go cable
  • GPS antenna and mounting hardware
  • user manual
The user manual is available for download.

The Ocean Signal ATB1 transceiver provides wired data communication using both the NMEA-0183 protocol and the NMEA-2000 protocol. The NMEA-0183 signals are provided in the Power-Data cable. There are two NMEA-0183 ports, with each port using the proper balanced signal configuration. Port 1 uses the standard NMEA-0183 wire color codes; Port 2 uses alternate wire colors.