Can middleware designed for terminal operations provide a wider technology choice?
Container terminals and port facilities are generally busy areas with the movement of cargo on and off the facility, and using heavy plant and equipment to handle the cargo. It is therefore not really a surprise that the use of radio frequency (RF) communications in this environment is quite widespread in order to aid the efficient management and monitoring of the cargo movements and status of the equipment and plant.
In ports and terminals, systems integrators utilize many types of RF communication for the transfer of operational and engineering data. This can vary from very short range systems to site wide networks.
Most short range applications are point to point devices or RFID type systems, such as container truck identification or security card access systems. These types of systems are used for driver authorization to permit use of the equipment. Short range systems are also implemented to reduce costs involved in cabling where this would be difficult to do.
However, when referring to port installations, inevitably one tends to think of the site wide wireless data networks, and most people will immediately think of a WiFi network; however this is not the only option, with several others being available, including Narrowband and GPRS (GSM).
Mention a site wide radio data network and you immediately think of an IEEE 802.11 network, or to give it its more common name, a WiFi network. These are very common in ports and terminals these days because they are very flexible and most applications can use them to connect through to mobile equipment. In fact we commonly use WiFi networks to connect management and monitoring software to mobile equipment for functions, such as position determinations systems (GPS enabled equipment and tracking systems), and automated asset management, telemetry, and equipment status condition monitoring.
WiFi networks, however, are not always practical, can be expensive on larger sites, and rarely operate reliably straight out of the box. Most WiFi networks operate in the 2.4 gigahertz frequency band and the maximum eradiated power allowed limits the range to approximately 100 meters to 140 meters. This effectively means on all but the smallest of sites multiple access points will be required to cover the site with a cohesive network. This, in my opinion, is the weakness of this type of technology, as the access points need to be in line with the site of the mobiles and will also need to be connected to the site Local Area Network (LAN). This can lead to gaps in the coverage and, to compensate for this, ITS write our mobile applications allowing for potential patchy WiFi coverage by building in local processing and data buffering. There are however some instances where the installation of a WiFi network is not possible or practical due to the lack of suitable access point locations or other reasons. An interesting recent example of this is the Messina Lines terminal at Genoa, Italy.
As part of a site wide upgrade project, Messina Lines had decided to replace its existing internally developed Terminal Operating System (TOS). The system selected offered mobile connectivity using a thin client over a WiFi network. However this became an issue at the Genoa terminal, as, in common with many terminals, the site is leased and construction of suitable additional structures to mount access points was not possible. A number of vendors were approached but a workable, reliable, proven solution could not be found using WiFi.
Traditionally, Narrowband technology was used with a direct connection to the TOS (running a computer screen emulation at a lower data rate bandwidth). However, when WiFi came along, with its much wider bandwidth and higher levels of data exchanges, most TOS systems developed their interfaces solely for this medium in mind. So, at Messina, the new TOS was only able to connect to a WiFi network, which of course the terminal wasn’t able to implement.
ITS have a long history using Narrowband technology in ports and terminals and have several Narrowband networks deployed. The feedback we get is that the users are happy with the Narrowband systems as the reliability is very high and has a range of several kilometers. This effectively allows a whole yard to be covered from a single transmitter with excellent coverage, even down between the containers in the stack.
Several years ago it became clear that TOS connectivity could become an issue for existing Narrowband users, so ITS started to develop the MRS middleware application. In its early days this was purely a translation programme to convert the bulky XML messages from the TOS in to a more streamline format that could transmit over the Narrowband network with its lower band width. The translation software was then connected to the existing radio frequency network management software (radio network server) and this then allowed all current TOS systems to connect to the Narrowband network and retain all the functions and features that modern terminals expect, making the Narrowband network completely transparent to the Terminal Operating System and the users alike.
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