Functional Vehicle On-Board Components
Vehicle Area Network
A Vehicle Area Network or VAN is a local area network in and around a moving vehicle. It enables devices in and around the vehicle to communicate, either directly connected or through wireless protocols over the Internet. A vehicle area network consolidates traffic from all the various devices and routes them over a network. By enabling the Vehicle Area Network, a vehicle becomes a definite end-to-end managed system that enables seamless integration of all network assets and applications under the umbrella of an Intelligent Vehicle System.
Before making any decision about the scope of implementation, a company should consider the following recommendations to build the bid upon. Any prospective VAN must deliver:
- Highest level of Scalability and Reliability
- Set of hi-speed, highly available data and voice connections – broadband, UHF, Cellular,
- Quick Setup times and easy migration path
- Small installation and maintenance foot-print
- Quick Connect unit's replacement and maintenance
- Open industrial standards, open development platforms, and interoperable infrastructure networks
- Conformance with relevant laws and standards
Mobile Data Computer
The concept of the modern in-vehicle mobile data computer (MDC), also widely know as mobile data terminal (MDT), prevails as a concept of a proposed design in the latest implemenations. Either addressed as "in-vehicle" or "on-board" mobile data terminal or integrated vehicle unit, it is essentially either an industrial computer specifically designed for transit applications or low-cost riggedized tablet PC. The modern MDC usually comes with a sleek touch screen design, providing a user interface for the vehicle operators to interact with the in-vehicle and on-board communication and control systems. Although the design and technology implementation has changed with Android OS being the prevalent operating system, the basic principles of human-machine interface (HMI) still dominates with a Graphic User Interface (GUI) philosophy based upon the similar navigation principles and layouts as the traditional keypad terminals.
In addition to the embedded "hands-free" microphone and speaker, the MDC should have a small embedded video camera that can stream live video based on predefined emergency or operational scenario (streaming live video when a red emergency button is pressed).
In addition to having to be rugedized at least to the IP65 rating, the touch screen MDC makes perfect business sense by providing the operational benefits of real-time data communications and Automatic Vehicle Location (AVL), and real-time messaging and voice communication between dispatch and vehicle operators. It combines the power of in-vehicle computing and the configurability of modern AVL navigation, yielding a comprehensive and easy to use multi-function communications tool. The operator is presented with a screen comprised of a series of web dispatcher-like overlays. These are a series of superimposed screens which are alternatively selected by touching a "screen tab." Touching an on-screen button, the operator will notify dispatch that the information was received and read. Other standard and custom text messages may be paged to the driver by dispatchers. These messages may be viewed, and then replied to, with the simple touch of on-screen buttons. The MDC provides ubiquitous AVL functionality:
- Vehicle operator logon and logoff, anti-theft system, Single-Sign-On (SSO) for all devices and applications on the vehicle
- Operator validation for correct vehicle, route and run initialization,
- Voice control, two way text messaging notifications, canned messages,
- Emergency alarm activating,
- Notification of route and schedule adherence and re-routes,
- Turn-by-turn graphical instructions,
- Next stop display, volume control, vehicle status (odometer, maintenance, ...),
- Controlling and operating the internal and external public announcing (PA) system,
- Monitoring of integrated in-vehicle and on-board peripheral systems.
As an advanced feature, the MDC should be able to provide two-way video control and communication between vehicle operator and the transit control centre. The on-screen keypad-based MDC provides similar functionality as its touch screen counterpart, but on an super bright AMOLED display.
Based on years of experience with robust interface design, the keypad MDC offers maximum reliability and minimum operator workload, based on the concept of integrated keypad with operator "smart keys". The MDC "smart keys" are used to access information quickly by scrolling or paging through information contained in the operators unit. The alphanumeric keypad can be used to speed specific data entries such as operator logon with minimal number of buttons pressed. To comply with the stringent environment industrial standards, both the touch screen and keypad-based MDC is enclosed in an environmentally safe ruggedized enclosure suitable for sustaining harsh public transit environments and installations. The MDC either integrates most of the "on-board" AVL functionalities, or it is connected with or integrated into the vehicle logic unit component.
Mobile Communication Platform
The in-vehicle ("on-board") mobile multi-network communication platform network should use the most available and economical spectrum and medium with optimal amount of bandwidth for anyone, anytime and anywhere. It must deliver seamless duplex (bi-directional) broadband communication solution for moving vehicles. The mobile communication platform supports Vehicle Area Network (VAN) secure communication between a vehicle's on-board information technology systems and off-board communication information system, delivering high performance and high security radio networking for mobile applications.
The IVS must migrate from the legacy set of protocols and adopt Internet Protocol (IP) protocols as a core internetworking layer. It should implement Ethernet as an address mapping protocol at the data link layer wherever it can, but it can also rely on fiber optic or wireless bridges whenever these services are available.
Considering the request for the support of the mobile triple play services (voice, data and video), the communication platform must deliver sufficient capacity for the existing needs and future scalability to met bandwidth and protocol requirements for envisaged applications. It provides a high level of flexibility, scalability, reliability, and manageability, and should reach a set of supported protocols including integrated compatibility with radio and wireless WAN standards: conventional and trunking UHF, Digital Mobile Radio (DMR), Digital Private Mobile Radio (dPMR), Project 25 (P25), EVDO, CDMA, GPRS, EDGE, UMTS, HSUPA, Wi-Fi 802.11 a/b/g/n, 4.9GHz Public Safety Broadband, HSPA, Wi-MAX 802.16 d/e, and future Long Term Evolution (LTE). The platform should embed or integrate a real-time GPS receiver interface, self testing and diagnostic capabilities and user friendly mobile communication platform management interfaces.
There is a group of vendors specializing in the mobile communication platform which comply with the Commission requirements. Marketed as "Mobile Broadband System", "Mobile Communication Gateway Router" or "onBoard Mobile Gateway", these systems utilize a wide range of private and public wide area networks including broadband wireless networks, cellular networks and analog and digital mobile radio standards. Their respective products are rugged, vehicle-mounted communications platforms that provide wireless access to broadband networks and assure continuous service by switching between multiple wireless networks. Although they vary by design, the typical Vehicle Area Network (VAN) mobile communication platform contains two distinct communication planes: wireless wide area network (WAN) plane and in-vehicle network (IVN) plane.
The WAN plane simplifies the vehicle communications architecture by consolidating communications and security capabilities for multiple on-board systems. It is configured with either embedded or plug-in modems to accommodate fleet access to multiple existing and future public and private broadband wireless, cellular and radio networks. The plug-in plug-and-play concept is preferred over embedded approach because it allows easier decommissioning of obsolete or unsupported networks and smooth migration to next generation of network services. It must have modems to support UHF 400 MHz band and CDMA networks supporting smooth system migration, as well as modems for the 802.11 a/b/g/n Wi-Fi communications and supporting radio antennae system on the roof of the vehicle. Depending on planning of the city wide network infrastructure deployment by the Commission or the City of Toronto, and availability of high-speed voice and data cellular and network services, the WAN plane supports network trends that provide vertical scalability:
- Digital Trunking with DMR or P25, TETRA
- Current 3G: EVDO, HSPA, UTMS, HSDPA,
- Current and future 4G: mobile Wi-MAX, LTE.
The WAN mobile gateway plan supports trunking and roaming with coverage area. When required, it automatically switches traffic between different networks according to pre-defined network selection policies. Under the "switched mode", the mobile gateway chooses the best available single channel for data transmission, and the switching is based on configurable parameters (like network availability, signal strength, usage fees) to establish seamless switching. In "aggregate mode", multiple channels are available for data transmission by allocating specific applications to specific data routes. The WAN plane offers the simplicity that any application that can run over a standard IP link can be run over the mobile gateway link.
The IVN plane is dedicated wired and wireless plane that makes the mobile gateway connections available to in-vehicle applications and passenger revenue systems. It must integrate with standard the MDC/AVL equipment of the leading transit dispatch system vendors, and provide IP-enabled interfaces for a number of in-vehicle applications: next stop announcement, video camera monitoring, vehicle health monitoring, automatic passenger counting, fare collection, next vehicle arriving, and driver safety systems. It should also provide shared connectivity support for the in-vehicle peripheral systems and near-vehicle wireless systems. This support spans over in-vehicle content distribution network (CDN), passenger internet access, passenger information system, or other additional services.
The IVS system should be incorporated in wider scope with other similar radio systems under an enterprise radio umbrella, and transform into a powerful digital trunking system. Through an upgrade of base station equipment and running terminals in analog mode with a smooth migration path to digital, the next generation radio network should evolve into an effective Digital Mobile Radio (DMR) system. The strength of DMR that differentiates it best from the rest like dPMR, OpenSky, APCO P25 and TETRA, is an open standard for conventional and trunked radio operation that offers a plethora of business gains going digital, including spectrum efficiency, equipment interoperability, digital audio clarity and data integration. This exciting renaissance of the DMR-based sion enterprise radio system that integrates all scarce radio channels resources addresses solidifying of the existing deployments, providing required system capacity for the imminent Transit City initiative, and an excellent radio network platform for future deployments and fulfilling long-term Commission radio bandwidth needs.
As embedded in its title, an IVS must play a much bigger role in pursuing the mission, vision and goals of the public transit servicing the public. While maintaining its aptitude in delivering mission-critical AVL and emergency services, the IVS must transfer acquired knowledge and leverage its years of experience has by building and maintaining up-to-date communication and information system supported by advanced wireless broadband infrastructure that will provide services for a large number of enterprise departments: revenue operations can definitely benefit from IVS tracking their revenue trucks, special constables can have much better visibility and respond to accidents quickly if they have access to traffic monitoring, marketing department can significantly enhance revenue by streaming revenue content over content distribution network display in vehicles, while system integration with Wheel-Trans may almost eliminate recurring network charges.
The RFI responses almost unanimously acknowledge that the IVS system provides unique communication requirements and challenges in achieving maximum performance and cost effective radio network solution. Although the Commission monitors changes of the frequency landscape in the upper 700 MHz spectrum and re-branding of the 800 MHz spectrum, the IVS should maintain long-term commitment to the existing IVS UFH 420-430 MHz frequency spectrum for the radio network plane. Not just because the signals in this spectrum tend to follow the terrain and penetrate vegetation well and the radio system Omni directional collinear antenna captures more energy than others, but also because that with nowadays RF technologies UFH radios provide cost-effective solutions.
It is certain that any of the RFI proposed communication network solutions, based on TAIT's DMR Trunking, Motorola's ASTRO 25 and MOTOTURBO, Kenwood NX-700, Harris's OpenSky, or Bell's 3G cellular networks, are capable of supporting next generation IVS applications. Further vendor neutral analysis of potential communication solutions upon selection criteria such as initial, recurring airtime and maintenance cost, deployment risks, system coverage and ownership, system interoperability and trunking lifts DMR solution high among competition in the radio communication plane. Above the digital din of others, the DMR provides higher level of flexibility, reliability, modular scalability, expandability, explicability and upgradeability. Utilizing existing IVS spectrum and channels, it provides both voice efficiency of one voice per 6.25 KHz channel spacing and achieves 4800 b/s raw data efficiency in 6.25 KHz bandwidth. The DMR trunking solution also known as "digital MPT" aims to provide improved operational trunking efficiency of the world's most successful MPT1327 trunking standard, while offering comprehensive migration strategy.
The ubiquity of Wi-Fi devices and people experiencing Wi-Fi wireless advantages will readily appreciate the ability to access the Internet on public transit. The economic importance of Wi-Fi connectivity rises dramatically in the face of convergence of cellular and Wi-Fi standards, and it is an opportunity for the Commission to increase revenue by providing in-vehicle Internet access over Wi-Fi.
The rapid innovation in intelligent public transportation systems, including advanced traffic management solutions and the existing in-vehicle video security systems that help detect safety issues, is exposing the need for vehicle Wi-Fi connectivity. The ability to connect these on-board applications with wayside servers using wireless technology is making the new breakthroughs a reality. With public transit in-vehicle applications becoming crowded and bandwidth precious, there is a need for an on-board converged IVS wireless mobile gateway, a computer networking device that routes packets from in-vehicle wireless local area network to wide area network, combining the functions of a wireless access point or bridge, and providing firewall functions. It integrates wireless connectivity for the vehicle camera, APC, SWASAS, Next Vehicle Arrival in-vehicle applications that require data exchange with on-ground application services. Similar Wi-Fi approach must be used for the connectivity on the Commission properties, particularly division garages and subway stations, in establishing campus-wide Wi-Fi enabled clouds. Having instant access to the Internet, and other application services irrespective of location can dramatically change the way public transit communicates. If wireless coverage is also converged with voice and video, the experience is even further enhanced.
The wireless broadband access and wireless backhaul technologies are ones the IVS WAN networks can benefit from tremendously in the future. Modern 3G and 3G+ protocols and services like CDMA, EVDO, HSPA, HSPA+ (HDSPA) are already widely and densely deployed all over big cities and wider by significant number of telecoms, leaving space for effective negotiations with service carriers. The 4G mobile Wi-MAX and Wi-MAX in 4.9 GHz public safety spectrum, as well as Long Term Evolution (LTE) and it's LTE Advanced variant, offer unprecedented high-speed communications and triple-play (voice, data, and video) services, unmatched characteristics that the IVS should take full advantage of deployed the network infrastructure.
There is an issue that has to be highly pointed out in the implementation of the new generation IVS system. Considering that quality and capacity of the voice communications have been considered as the "Achilles' heel" of the existing AVL systems, the next generation IVS system must support robust, highly reliable voice communications between dispatcher centre and vehicle operators. The system must implement robust voice (preferably digital) trunking mechanism that has faster call set-up, emergency calling, the ability to queue calls when the called party is not available, supporting one-to-one, fleet and group calls, broadcast, priority and emergency calling.