Mobile computing:Ocean of technology in the hands.

Mobile computing is human–computer interaction by which a computer is expected to be transported during normal usage. Mobile computing involves mobile communication, mobile hardware, and mobile software. Communication issues include ad hoc and infrastructure networks as well as communication properties,protocols, data formats and concrete technologies. Hardware includes mobile devices or device components. Mobile software deals with the characteristics and requirements of mobile applications.

Mobile computing is "taking a computer and all necessary files and software out into the field."

"Mobile computing: being able to use a computing device even when being mobile and therefore changing location. Portability is one aspect of mobile computing."

"Mobile computing is the ability to use computing capability without a pre-defined location and/or connection to a network to publish and/or subscribe to information." Uwe Vieille, ACM.org/

Devices

Many types of mobile computers have been introduced since the 1990s including the:

• Personal digital assistant/enterprise digital assistant
• Smartphone
• Tablet computer
• Ultra-Mobile PC
• Wearable computer

Limitations

• Range & Bandwidth: Mobile Internet access is generally slower than direct cable connections, using technologies such as GPRS and EDGE, and more recently HSDPA and HSUPA 3G and 4G networks. These networks are usually available within range of commercial cell phone towers. Higher speed wireless LANs are inexpensive but have very limited range.
• Security standards: When working mobile, one is dependent on public networks, requiring careful use of VPN. Security is a major concern while concerning the mobile computing standards on the fleet. One can easily attack the VPN through a huge number of networks interconnected through the line.
• Power consumption: When a power outlet or portable generator is not available, mobile computers must rely entirely on battery power. Combined with the compact size of many mobile devices, this often means unusually expensive batteries must be used to obtain the necessary battery life.
• Transmission interferences: Weather, terrain, and the range from the nearest signal point can all interfere with signal reception. Reception in tunnels, some buildings, and rural areas is often poor.
• Potential health hazards: People who use mobile devices while driving are often distracted from driving and are thus assumed more likely to be involved in traffic accidents.(While this may seem obvious, there is considerable discussion about whether banning mobile device use while driving reduces accidents or not.) Cell phones may interfere with sensitive medical devices. Questions concerning mobile phone radiation and health have been raised.
• Human interface with device: Screens and keyboards tend to be small, which may make them hard to use. Alternate input methods such as speech or handwriting recognition require training.

In-vehicle computing and fleet computing

Many commercial and government field forces deploy a ruggedized portable computer with their fleet of vehicles. This requires the units to be anchored to the vehicle for driver safety, device security, and ergonomics. Rugged computers are rated for severe vibration associated with large service vehicles and off-road driving and the harsh environmental conditions of constant professional use such as in emergency medical services, fire, and public safety.

Other elements affecting function in vehicle:

• Operating temperature: A vehicle cabin can often experience temperature swings from -20F to +140F. Computers typically must be able to withstand these temperatures while operating. Typical fan-based cooling has stated limits of 95F-100F of ambient temperature, and temperatures below freezing require localized heaters to bring components up to operating temperature (based on independent studies by the SRI Group and by Panasonic R&D).
• Vibration can decrease the life expectancy of computer components, notably rotational storage such as HDDs.
• Visibility of standard screens becomes an issue in bright sunlight.
• Touchscreen users easily interact with the units in the field without removing gloves.
• High-temperature battery settings: Lithium ion batteries are sensitive to high temperature conditions for charging. A computer designed for the mobile environment should be designed with a high-temperature charging function that limits the charge to 85% or less of capacity.
• External antenna connections go through the typical metal cabins of vehicles which would block wireless reception, and take advantage of much more capable external communication and navigation equipment.

Several specialized manufacturers such as First Mobile Technologies, National Products Inc (Ram Mounts), Gamber Johnson and LedCo build mounts for vehicle mounting of computer equipment for a wide range of vehicles. The mounts are built to withstand the harsh conditions and maintain ergonomics.

Specialized installation companies design the mount design, assembling the parts, and installing them in a safe and consistent manner away from airbags, vehicle HVAC controls, and driver controls. Frequently installations will include a WWAN modem, power conditioning equipment, transceiver antennae mounted external to the vehicle, and WWAN/WLAN/GPS/etc.