Central Data Server [CDS]

The MariWeb™ CDS is the primary component of the MariWeb™ AIS suite of software and contains the primary active database along with the AIS Service Management [ASM] functionality. The ASM has the Basic AIS Services [BAS] as defined in the IALA A-124 Recommendation.

The ASM module also allows for the capture and testing of a complete network configuration definition according to the rules in the IALA A-124 Recommendation. This is done without downloading any of the data to the PSSs connected to the MariWeb™ AIS network. Once the network configuration has been downloaded to the MariWeb™ network or part thereof, a verify background task checks the configuration of the AIS Physical Shore Station [PSS] and nodes and alerts are generated when configuration changes.

AIS data is collected at the CDS from all of the AIS PSSs via the WAN, all duplicates are eliminated (except for the metadata), time stamped with time of arrival and source, verified and then stored in the Vessel Location Register [VLR]. The VLR is a high performance database  and allows processing of the AIS data in real-time before storage in the primary SQL database (or other selected database) running on a COTS server. 

AIS data can also be obtained from another database or data logging system as an offline AIS data feed, from other AIS networks in IEC61162 or XML format or from a Lloyds Maritime Intelligence Unit [LMIU] or similar data feed. MariWeb™ connections are normally RS232C, RS422 or TCP/IP. Where UDP is required this is provided but not recommended due to the ‘fire and forget’ nature of UDP communications methods and therefore lack of confirmed data delivery.

All incoming AIS data is stored in the primary database as an audit trail ensuring that all data is available in original (as received and not changed, processed or reconstituted) and in parsed format being human readable allowing export in Comma Separated Variable [CSV] format or XML via a Web Service or via an SQL query for further analysis. A ships database is available that stores all the static data for each vessel that is detected by the MariWeb™ system over its operational life. This provides an up to date record of all vessel fitted with AIS units and can be configured to raise an alert for the operator should the ships static AIS data change at any time.

The MariWeb™ CDS is protected by a complex firewall.

Base Station Controller [BSC]

 The MariWeb™ BSC contains a significant part of an AIS network and can be configured to include a MariWeb™ Chart System [MCS] so that a user can connect directly to the BSC and have a significant portion of the total AIS network functionality including the ability access to the full configuration capability.

All incoming data is stored on a local nonvolatile for at least two weeks but can be configured for up to two months. If and when the WAN link to the CDS fails are is unable to carry the full data load for whatever reason, the unsent data is flagged on the BSC. Once the link is restored to full (or even partial operation), the BSC measures the data link capacity heuristically on a regular basis and then use this information to transfer any unsent data in a priority order to the CDS using the IMIS Global Limited 'Quick Restore' process.

This ensures that the safety of the AIS network and all vessels and AtoN is preserved even when a link fails and returns to normal operations.

The BSC is constructed using tried and trusted industrial controller hardware with a wide operating temperature range and having low power consumption and high performance.

The MariWeb™ BSC is constructed to allow for two BSCs to be able to operate in a redundant mode at the same site, should this ever be required.  The BSC includes a firewall to detect and prevent faulty AIS signals from entering the AIS network WAN and the rest of the AIS network and display system.