The Gateway to a Better Vehicle Area Network Key considerations when evaluating laptops as communications hubs for in-vehicle communications
Introduction Since notebooks first incorporated internal Wi-Fi radios, computer makers have been designing antennas into their portables. The design goal was simple: connect to a nearby access point. These early antennas were simple pieces of stamped metal and they worked fine unless they were bent during installation or repairs. The evolving demand for rugged and reliable mobile workforce products means internal antenna design is now more effective. Antennas perform far better and are rarely damaged during installation. Serious attention is given to all aspects of radio performance, including antenna placement and wire routing to minimize interference and losses. Antenna Pass-Thru Traditional portable computers work fine in an office setting, but deliver less than stellar performance when signal strength is low. In a vehicle environment, signal strength, like everything else, is changing from moment to moment. To deal with this, many manufacturers have routed antenna wires to a port on the dock, and installers are able to attach external antenna. This brute-force method works fine, and if installed correctly and computers are properly configured, they can improve their connectivity, but at a significant cost. Pro s and Con s of Antenna Pass-Thru Antenna pass-thru designs can only improve radio performance when correctly installed and attached to external antenna. However, radio performance of the internal antennas is degraded when the external antenna is not attached. This is because every connection point in the antenna circuit degrades performance. Therefore, there is a major compromise when adding an external antenna to a Notebook or Tablet: wireless performance of a portable computer or mobile tablet is diminished when the external antenna is not used. This is because the extra circuitry required to switch between external and internal antennas compromises the performance of the system. Greater cable lengths and more connectors combine to result in a serious loss in signal strength. State of the art mobile devices incorporate sophisticated circuitry to find radio signals amid reflections, noise and interference. One example is MIMO (Multiple Input, Multiple Output), which uses two internal antennas to reduce multipath effects and connect to weaker signals. The other advantage of MIMO is that when signal strength is good, the radio uses both antennas to transmit 2
and receive simultaneously, doubling the bandwidth. However when an external antenna is used, the MIMO system can t hear the difference between antenna (since there is now only one), and data rates are halved. So while an antenna attached to a computer can add signal sensitivity, it then reduces any gains by using multiple connectors and prevents MIMO functionality. Three steps forward, two steps back. Mobility is Different than Portability For a long time, computers installed in trucks and patrol cars were heavy and bulky. They were portable in the sense that the vehicle could take them anywhere, and they were occasionally undocked and removed from the vehicle, but they were not easily used outside the vehicle so productivity gains stopped at the vehicle door. Since most portable computers used in vehicles were essentially permanently installed, performance using the internal antenna was sufficient. Productivity increases demanded by today s organizations has driven technology to provide solutions that can be used wherever people need to use them and at any time. Today s tablets are rugged, durable, thin, lightweight, and have screens designed to be viewed outdoors. These mobile tablets are designed to be used in the office, in the vehicle and in the field. Mobile devices rely heavily on network connectivity, so whether they are tablets, smartphones or IP-based cameras, they need to be on-line. This is ushering in a new approach to invehicle wireless networks. Modern Workflows Today s productive mobile workers have an array of wirelessly connected devices: smartphones, tablets, and cameras to name a few. Mobile devices need connectivity. While antenna pass-thru supports one device, and only when it was docked, it does not address the needs of all of the wireless devices present inside and outside of today s service vehicles. Some notebook computers were configured as an access point for other devices. That made sense when the notebook was permanently installed, but what happens when 3
highly mobile tablets are used? If they used antenna pass-thru technology, the moment they are undocked, their wireless performance degrades dramatically. The modern approach is to use a mobile gateway to connect all the devices. Gateways connect to the cellular data network by using multiple high-gain mounted antennas and are capable of delivering the speed and sensitivity advantages that MIMO technology offers. They offer a secure Wi-Fi subnet over hundreds of feet, allowing network connectivity to all IP devices for seamless performance, inside and outside of any vehicle. Mobile Gateway Capabilities Mobile gateways maximize your options by offering a variety of capabilities. Permanently installed and hard-wired into the vehicle power source, they connect to external antennas and feature an assortment of internal radios. Often using Wi-Fi to talk to multiple devices, the separate radio for WWAN can share its connection efficiently with all devices that need Internet access. The deployment of a mobile gateway creates a robust Vehicle Area Network (VAN), turning the vehicle and its surrounding area into a true mobile office. Some of advantages of a gateway enabled VAN include: 4
Every IP device in or around the vehicle gets network access Most devices used in a public safety or utility environment work better if connected to the Internet. Tablets are one such device, as are smartphones, IP based cameras and other devices such as electronic ticket printers, finger print scanners and man-down alarms. Reliability and Durability Mobile gateways are built with connectivity as their sole purpose. Leveraging a mobile gateway to be a connectivity hub ensures the most reliable and consistent connection. Since a gateway is hardwired into the vehicle s power supply it can maintain a persistent secure connection to your corporate network resulting in near 100% up-time, and with auto ignition sense, it turns on and connects with no manual intervention. Furthermore, in the event of disconnect with the network, the gateway is designed to re-connect automatically, ensuring reliable connectivity for your Vehicle Area Network. Mobile gateways are also built to withstand the rigorous environments that in-vehicle solutions demand. No matter what the environmental conditions, your Vehicle Area Network will stay connected, ensuring that all of your devices are on-line. Everything has network access even if the computer is removed, broken or turned off Some organizations use the installed PC as a Wi-Fi hotspot. While this may seem like an efficient solution, it severely limits the availability of a Wi-Fi network (i.e. once the computer is removed from the dock, powered off or disabled, all devices in the vehicle lose their connection). A mobile gateway provides one secure shared connection to all of your devices. This connection is not dependent on a computer in the vehicle. Mobile gateways are designed to be robust and reliable their mission is delivery of wireless access to multiple devices, and they perform this mission well. Cost savings - Every IP device shares one data-plan Use of a gateway offers the opportunity to consolidate the data plans from multiple devices into one shared plan. With devices sharing a single connection, there are obvious cost savings to be realized. 5
Remote Management Remote management is a key component in any fleet deployment. It s vital for IT managers to have access to the health and status of communications links and be able to maintain, update and troubleshoot when necessary. Many gateway providers offer tools that enable IT staff to perform comprehensive remote management and configuration of not only the communications gateway, but also the peripheral equipment connected to that gateway. With a comprehensive remote management tool, an agency s IT department can proactively manage software versions and configurations to improve the accessibility, security and performance of their network without having to take vehicles out of service or return individual devices for upgrades. This feature enables a fleet to have minimal downtime, while functioning at optimal performance. VPN Endpoint To protect sensitive data, many organizations deploy a VPN for their fleet of gateways to communicate with back-office applications. An advantage of a mobile gateway is that is can act as the VPN endpoint, thereby providing a persistent VPN tunnel (IPsec, PPTP, etc.) to the enterprise network behind the firewall. This means that each client device does not have to establish its own VPN tunnel and will automatically have IP connectivity to the enterprise network and resources associated with the mobile gateway. Future upgrades Utilities and public safety agencies that deployed 3G-based gateways can upgrade or replace them with 4G-LTE gateways. With one upgrade, every device in the vehicle is upgraded to a faster connection. The newest cellular-based network coming on line for Public Safety is FirstNet. Once FirstNet is available, simply upgrading the mobile gateway will deliver this important network capability. You do not need to replace individual devices to make use of a new cellular data network. Optimal installation for peak performance The best performing radios have short cable runs from the radio to the antenna, with a minimum of connectors. Mobile gateways achieve this by being able to have a very short run to the antenna. 6
In contrast, antennas that are connected to a notebook vehicle dock have long antenna cable runs because they need to be routed from the dock to the roof of the vehicle. Longer cable runs result in higher signal loss. Another factor degrading signal strength is the number of connectors. A solution with antenna pass-thru is burdened with multiple connectors both inside the computer and inside the docking station. Every connection adds up to a significant signal loss negating most of the advantages of this type of solution. A gateway mounted close to the vehicle body with short wiring and the minimum distance to the antennas will provide the strongest performance with least amount of signal loss. Tuning your wireless capabilities to your unique signal-strength issues Mobile gateways have more flexibility to support challenges in your geographical area. Some even support multiple carrier data cards simultaneously. There are some gateway providers that will map your area so that you will know which locations are best served by which carrier or carriers. Automated Emergency Alerts Your officers or technicians are on the front lines, dealing with challenging situations and the public. When there is an emergency, they are busy dealing with the situation before they are even able to report in. Some mobile gateways can be set up to trigger events in the vehicle and provide immediate alerts to headquarters. For example, the on-board diagnostic (OBD) ports on vehicles sold since 1996 can support a dongle which transmits important events such as airbag deployment, heavy braking or excessive speed. Police cars can also add input/output switches to the shotgun rack to report when it is removed, or use a microphone to generate an alert when there is a gunshot. There are many examples like this for various types of fleets (e.g. Man down alarm, K-9 door deployed) that increase the safety of officers and service technicians that are only possible with the use of an in-vehicle gateway. 7
Integrated with your Computer Aided Dispatch Systems Mobile gateways can include highly sensitive GPS receivers so GPS location can be sent to your Computer-Aided Dispatch (CAD) system. This type of deep integration with CAD and Automatic Vehicle Location (AVL) systems make an in-vehicle gateway the optimal hub for all vehicles in a fleet. Use a best-in-class mobile gateway for your needs There are many mobile gateways available with differing capabilities and upgrade options. The alternative is to accept the features of the computers wireless radio that happens to be installed in your device. These are often fixed devices with few options and no upgrade path. Conclusion Gateways provide much more than simple connectivity As utilities and public safety agencies looked to increase their productivity, they embraced computers and installed them in their vehicles. They often had to use external antennas connected to the computer to get satisfactory connectivity. While that made sense in the past, today s mobile workers have an array of wireless devices and they all need network access. Mobile Gateways deliver superior wireless performance, support all wired and wireless networked devices, and provide a host of other advantages. Most importantly, they enable the mobility demanded by today s users of tablets, smartphones, IP cameras and other mobile devices. Many agencies have adopted antenna pass-thru as their connectivity solution, which solved one problem connectivity for one device and only while docked. Mobile gateways create a secure wireless network infrastructure that supports connectivity for all devices, can support vehicle data monitoring, location services and many other functions. The demand for increased productivity has driven a revolution to support workers in the field, not just in the truck. This revolution demands a state of the art wireless solution. A lightweight, rugged tablet may be the most useful device for the driver of a fleet vehicle to complete his day-to-day tasks. A robust in-vehicle gateway is the optimal tool for turning 8
the vehicle and its surrounding area into a true mobile office. An in-vehicle gateway also has superior network performance over a laptop with antenna pass-thru. An installed gateway can provide connectivity to all devices in and around a service vehicle, track precise GPS location, monitor events and performance of the vehicle/driver, and can be integrated with an existing CAD system. The flexibility, reliability, versatility, manageability and superior antenna performance of an in-vehicle gateway make it the ideal solution for creating a Vehicle Area Network for any fleet. About Sierra Wireless Sierra Wireless is building the Internet of Things with intelligent wireless solutions that enable organizations to innovate in the connected world. We offer the industry s most comprehensive portfolio of 2G, 3G and 4G embedded modules and gateways, seamlessly integrated with our secure cloud and connectivity services. OEMs and enterprises worldwide trust our innovative solutions to get their connected products and services to market faster. Sierra Wireless has more than 900 employees globally and operates R&D centers in North America, Europe and Asia. For further company and product information, please visit www.sierrawireless.com. 9