Introduction to Wireless Communications

Fixed Broadband Wireless

• In areas where wired Internet connectivity may not be available
  • Solution may be to deploy wireless links based on microwave data equipment or WiMAX
• These technologies are commonly called fixed broadband wireless
• T1 lines
  • Very costly option
• Cable modems
  • Generally only available in residential areas

• Digital subscriber lines (DSL)
  • Use either regular or special telephone lines – Speed is dependent on distance between FPE’s main office and nearest telephone switching office
• Wireless metropolitan area network (WMAN)
  • Covers a distance of up to 25 miles
  • Based on the IEEE 802.16 WIMAX Fixed Broadband Wireless standard
  • Uses radio waves and small custom antennas on the roof of each building in WMAN

• WMAN (WiMax)

– Transmission speeds

• 75 Mbps at distances of up to 4 miles (6.4 km)
• 17 to 50 Mbps at distances over 6 miles (10 km)

– Recent amendment of IEEE 802.16m standard can achieve average speeds up to 100 Mbps and up to 1

Gbps in a point-to-point link

The Wireless Landscape

Digital Convergence and Future Trends

• Digital convergence
• Refers to the power of digital devices to combine voice, video, and text-processing capabilities
• As well as to be connected to business and home networks and to the Internet
• The same concept applies to the development of VoIP networks
• Use the same protocols and media that once only carried data
• Wireless technologies are used to fulfill many daily activities

Wireless Advantages and Challenges

• As with any new technology, wireless communications offers both advantages and disadvantages

Advantages of Wireless Networking

• Mobility
• Freedom to move about without being tethered by wires
• Permits many industries to shift toward an increasingly mobile workforce
• Creating “flatter” organizations with fewer management levels between top executives and regular employees

Advantages of Wireless Networking

• Easier and Less Expensive Installation
  • Installing network cabling in older buildings can be a difficult, slow, and costly task
  • Makes it easier for any office to be modified with new cubicles or furniture
  • Installing network cabling can usually take days or even weeks to complete
• In countries where labor costs are high, this can make it very expensive

Advantages of Wireless Networking

• Increased reliability
  • Network cable failures may be the most common source of network problems
  • Eliminating cable failures increases the overall reliability of the network
• Disaster recovery
  • In the event of a disaster, managers can quickly relocate the office
  • Some planners keep laptop computers with wireless NICs and access points in reserve

Challenges of Wireless Networking

• Radio signal interference
  • The potential for two signals to interfere exists
  • Common office devices that could cause interference:
• Microwave ovens
• Elevator motors
• Heavy electrical equipment
• Outdoor lighting systems
• Theft protection systems
• Cordless telephones
• Solution: locate the source of interference and eliminate it

Challenges of Wireless Networking

• Security
• It is possible for an intruder to be lurking outdoors with a laptop computer and wireless NIC
• With the intent of intercepting the signals from a nearby wireless network
• Some wireless technologies can provide added levels of security
• Network managers can limit access to the network by programming it with a list of approved devices
• Rogue APs can be connected to a wired network by a disgruntled employee

Challenges of Wireless Networking

• Health risks
• High levels of RF can produce biological damage through heating effects
• Wireless devices emit low levels of RF while being used
• No clear picture of the biological effects of this type of radiation has been found to date
• Science today does not yet permit anyone to draw a definitive conclusion on the safety of wireless mobile devices
• Be aware of the possibility and monitor ongoing scientific research

Summary

• Wireless communications is quickly becoming the standard in the business world
• There are many different types of wireless networks and devices
• Wireless wide area networks will enable companies of all sizes to interconnect their offices
• Without the high cost charged by telephone carriers for their landline connections
• RFID and NFC short-range wireless have revolutionized counting inventory, item identification, and payment systems
• Digital convergence refers to the fact that data networks today carry digitized audio, video, and graphics in addition to other types of data
• Mobility is the primary advantage of a WLAN
• Other advantages include easier and less expensive installation, increased network reliability, and support for disaster recovery
• Challenges to a WLAN include:
• Radio signal interference, security issues, and health risks may slow down growth of these technologies