system known as dead reckoning. The TRUMP unit also allows vehicle and CIS operators to send and receive text messages for such things as short turns and route adjustments. There is also the option of voice-based communication between the vehicle and CIS operators. With the introduction of NextBus technology to provide real-time arrival information, the CIS has been updated to use a combination of GPS data and the previous dead reckoning (signpost-based) system. In the event that internally managed TTC communications are unavailable, the TRUMP unit operates on Bell Mobility's CDMA network to communicate with divisional operations and transit control. In 2012, the TTC began research into transitioning from the outdated and antiquated CIS to a newer computer-aided dispatch (CAD) system. Utilizing this technology would help improve headways, provide more reliable communications and allow divisional supervisors to locate vehicles in real time (the current GPS system only sends location updates every 20 seconds). Implementation of the system, later named the Vehicle Information System & Integrated Operations Network (VISION), began in 2016, with the contract for associated equipment awarded to Clever Devices ULC. After extensive testing, deployment of VISION on vehicles in revenue service began in the summer of 2018, with plans to fully equip the entire bus and streetcar fleet by 2019. The third system, known as the "wayside system", consists of UHF MPT-1327 Trunking radio sets used by the three heavy-rail subway lines. They replaced older devices which communicated by the third rail, and are divided into separate systems representing their respective subway lines. This trunking system allows Transit Control to communicate directly with a single train, a zone encompassing several trains, or the entire line. (Line 3 Scarborough uses a single channel UHF system, much the same as the system used by operations staff.) All of these systems can be monitored by a scanner capable of the UHF Low band (406–430 MHz). Numeric codes—often referring to people or positions (299 Bloor – Subway Line mechanic at Bloor)—are also announced through the radio and the overhead paging system. The TTC also has several "Plans" ("Plan A" through "Plan G") that are used in emergencies but are not announced on the PA system and only referred to on the radio. OneStop media system The TTC, in partnership with Pattison OneStop (formerly OneStop Media Group), have installed large LCD television screens in most subway stations throughout the system except on Line