Survey of Wireless Computing School Of Computer Science Florida International University Abstract Wireless technology can provide many benefits to computing including faster response to queries, reduced time spent on paperwork, increased online time for users, just-in-time and real time control, tighter communications between clients and hosts. Wireless Computing is governed by two general forces: Technology, which provides a set of basic building blocks and User Applications, which determine a set of operations that must be carried out efficiently on demand. This paper summarizes technological changes that are underway and describes their impact on wireless computing development and implementation. It also describes the applications that influence the development and implementation of wireless computing and shows what current systems offer. 1 Introduction Wireless computing is the topic of much conversation today. The concept has been around for some time now but has been mainly utilizing communication protocols that exist for voice based communication. It is not intended to replace wired data communication but instead to be utilized in areas that it would be otherwise impossible to communicate using wires. Only recently has the industry been taking steps to formulate a standard that is more suitable to data transmission. Some the problems to be overcome are: (1) Data Integrity - relatively error free transmission, (2) Speed - as close as possible to the speed of current wired networks, (3) Protection - making sure that the data now airborne is encoded and cannot be tapped by unwelcome receivers, (4) Compatibility - ensuring that the many protocols that sure to be created subscribe to a standard to allow inter-operability, (5) Environmentally safe - strengths of electromagnetic radiation must be kept within normal levels. In our study of the theories and implementation concerns of wireless computing, we found that it is being treated in an object oriented fashion. Scientists and development crews, including the IEEE, are doing their best to implement wireless connectivity without changing the existing computer hardware. As a result, a lot of focus is on using existing computer hardware and software to convert data to a format compatible with the new hardware which will be added to the computer using ports or PCMCIA connections that already exist. This means that wireless communication will be transparent to the user if and when wireless computing is utilized on a wide scale. Wireless computing applications covers three broad areas of computing today. Replacement of normal wired LAN\'s need to retain the speed and reliability found in wired LAN\'s. Creation of semipermanent LAN\'s for quick and easy setup without the need for running wires. This would be necessary for events such as earthquakes. The last category is that of mobile computing. With advent of PCMCIA cards, notebook computers are being substituted for regular desktop machines with complete connectivity of the desktop machine. However, you lose the connectivity when out of the office unless you have a wireless means of communicating. On the compatibility issue, the ability to mix wireless brands on a single network is not likely to come soon. The IEEE Standards Committee is working on a wireless LAN standard -- 802.11, which is an extension of the Ethernet protocol. Because the field of wireless communication is so broad, the IEEE was not able to set a standard by the time private researchers were ready to test their theories hoping to set the standard for others to follow. 2 Methods There are a few methods of wireless communication being theorized and tested. (1) Radio: This is the method that makes use of standard radio waves in the 902 MHz to 928 MHz frequency range. Although these frequencies are well used, methods have been developed to ensure data integrity. Spread spectrum transmission of data is a method where the transmitter will send information simultaneously out over many frequencies in the range increasing the change that all data will eventually reach the receiver. Frequency hopping is an additional measure that also enables data security. The 26 MHz range of frequencies is further divided in to channels. The transmitter then sends out data hopping from one channel to the next in a certain pattern known to the receiver. Within each channel, spread spectrum transmission can be used to maintain interference avoidance. Some of this transmission manipulation can be avoided by transmitting at