Mobile Computing

1. Mobile Computing • Mobile computing is the discipline for creating an information management platform, which is free from spatial and temporal constraints. The freedom from these constraints allows its users to access and process desired information from anywhere in the space. The state of the user, static or mobile, does not affect the information management capability of the mobile platform. • A user can continue to access and manipulate desired data while travelling on plane, in car, on ship, etc. Thus, the discipline creates an illusion that the desired data and sufficient processing power are available on the spot, where as in reality they may be located far away. • The discipline of mobile computing has its origin in Personal Communications Services (PCS).

2. History Behind Mobile computing • In mobile computing platform information between processing units flows through wireless channels. The processing units are free from temporal and spatial constraints. That is, a processing unit (client) is free to move about in the space while being connected to the server. • This temporal and spatial freedom provides a powerful facility allowing users to reach the data site and the processing site (the geographical location where a processing must be performed) from anywhere. This capability allows organizations to set their offices at any location.

3. Historical milestones • April 7, 1928: The first mobile radio system went into operation in Detroit. It was used by the Detroit Police Department. • Year 1935: Frequency modulation has been developed and tested. • Year 1943: AT&T developed and introduced the Improved Mobile Telephone Service (IMTS). It consisted of a broadcast system with a higher-power transmitter. This system was followed shortly with limited cellular networks and the implementation of the first mobile radio system to connect with a fixed telephone number. • Year 1950s: Paging systems began to appear. During this period, Bell Labs continued to test the cellular techniques. • Year 1970: Federal Communication Commission (FCC) allocated spectrum space for cellular systems. At this time, AT&T proposed the cellular system that is now known as the Advanced Mobile Phone System (AMPS). • Year 1983: The cellular service was commercially implemented in Chicago and Baltimore.

4. Mobile connectivity: • The mobile connectivity between two nodes exists if they are continuously connected through wireless channel, and can utilize the channel without being subjected to spatial and temporal constraints.

5. A mobile device • "A mobile device (also known as cell phone device, handheld device, handheld computer, and palmtop or simply handheld) is a pocket-sized computing device, typically having a display screen with touch input or a miniature keyboard."  • Mobile devices are classified into various groups: (1)Mobile computers : Notebook PC, Ultra-Mobile PC, Handheld PC, Personal digital assistant/Enterprise digital assistant, Graphing calculator (2) Handheld game consoles  (3) Media recorders: Digital still camera, Digital video camera, Digital audio recorders (4) Media players/displayers : Portable media player, e-book reader  (5) Communication devices : Mobile phone, Cordless telephone, Pager (6) Personal navigation devices . (7) Other accessories

6. APPLICATIONS OF MOBILE COMPUTING • The question that always arises when a business is thinking of buying a mobile computer is "Will it be worth it?" • For Estate Agents • Emergency Services • In courts • In companies • Stock Information Collation/Control • Credit Card Verification • Taxi/Truck Dispatch • Electronic Mail/Paging • Airline and Railway Industries • Banking and Financial Institutions • Insurance & Financial Planning • Transportation Industry • Hospitality Industry • Manufacturing & Mining Industries

7. Research Issues in Mobile Computing • Wireless Communications Quality of connectivity Bandwidth limitations • Mobility Location transparency Location dependency • Portability Power limitations Display, processing, storage limitations

8. Challenges of Mobile Computing 1.Power • Mobile platforms spend much of their time attached to AC power. At those times they are like other desktops. Intel AMT can operate even when the platform is powered down, and it can be configured to operate in a low power state until it is awakened due to an external stimulus from the network. • When a mobile platform is operating on batteries (DC power) or even when the platform is asleep on battery power, it is essential to minimize DC power use, which means setting limits to Intel AMT activity on DC power. 2.Multiple Network Connections • Manageability network traffic can be present on both side of the network connections simultaneously

9. Challenges of Mobile Computing Security in a Wireless Environment • Wireless traffic requires additional protection beyond that used on a standard wired LAN • A wireless network access point must verify the identity of a device attempting to connect to it and validate that the device is authorized to connect to the network Working Inside and Outside the Enterprise • When a mobile platform is outside of the enterprise network and is connected to a foreign network (for example, at home, in an airport or hotel, or at a customer site), it cannot be managed by a management console inside the enterprise network.

10. Portability • Low Power Limited compute performance Low quality displays • Loss of Data Easily lost Must be conceived as being “network-integrated” • Small User Interface Limited real estate for keyboards Icon intensive/handwriting/speech • Small Local Storage Flash memory rather than disk drive

11. Personal Communications Services (PCS) • PCS (personal communications service) is a wireless phone service similar to cellular telephone service but emphasizing personal service and extended mobility. It's sometimes referred to as digital cellular • PCS is for mobile users and requires a number of antennas to blanket an area of coverage. As a user moves around, the user's phone signal is picked up by the nearest antenna and then forwarded to a base station that connects to the wired network. The phone itself is slightly smaller than a cellular phone. • PCS is designed for greater user mobility. It generally requires more cell transmitters for coverage

12. PCS (personal communications service)

13. PCS (personal communications service) • PSTN:Public Switched Network.MSC:Mobile Switching Center. Also called MTSO (Mobile Telephone Switching Office)BS:Base StationMS:Mobile Station Also called MU (Mobile Unit) or Mobile Host (MH)HLR:Home Location RegisterVLR:Visitor Location RegisterEIR:Equipment Identify RegisterAC:Access Channel

14. Network architecture

15. PCS • Several technologies are used for PCS is, including Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), and Global System for Mobile (GSM). communication. • PCS FREQUENCY ALLOCATIONS

16. PCS • PCS are connected to Public Switched Telephone Network (PSTN) to provide access to wired telephones. PCS include high-tier digital cellular systems for widespread vehicular and pedestrian services and low-tier telecommunication system standards for residential, business, and public cordless access applications. High-tier digital cellular systems include • Global System for Mobile Communications (GSM) • IS-136 TDMA based Digital Advanced Mobile Phone Services (DAMPS) • Personal Digital Cellular (PDC) • IS-95 CDMA-based cdmaOne System Low-tier telecommunication systems include • Cordless Telephone 2 (CT2) • Digital Enhanced Cordless Telephone (DECT) • Personal Access Communication Systems (PACS) • Personal Handy Phone Systems (PHS)