SPU Information Science Institute of Sripatum University Sripatum University 1 IS516 Computer Communication and Networks กกกกกกกกกกกกกกกกกกกกกกกกกกกกกกกกก Asst.Dr.Surasak Mungsing [email protected][email protected]http://www.spu.ac.th/teacher/surasak.mu
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
SPU
Information Science Institute of Sripatum University
Information Science Institute of Sripatum University
Topic Introduction to Wireless Technologies Wireless Networking Overview Non-Technical considerations Other Comparable Technologies
SPU
Information Science Institute of Sripatum University
4
Access Access Point Point
Wireless NIC cardsWireless NIC cards
SPU
Information Science Institute of Sripatum University
5
SPU
Information Science Institute of Sripatum University
6
SPU
Information Science Institute of Sripatum University
7
SPU
Information Science Institute of Sripatum University
What is Wi-Fi Wi-Fi is an abbreviation for Wireless Fidelity
and a catch all phrase for the several different standards and recommendations that comprise wireless networking.
Wi-Fi enables the user to deploy a computer network without needing to run cable throughout the facility.
SPU
Information Science Institute of Sripatum University
Standard: IEEE 802.11b –2.4GHz - 11 MbpsInternational standard for wireless networking that operates in the 2.4 GHz frequency range (2.4 GHz to 2.4835 GHz) and provides a throughput of up to 11 Mbps with a range of just over 300 feet indoors. This is a very commonly used frequency. Microwave ovens, cordless phones, medical and scientific equipment, as well as Bluetooth devices, all work within the 2.4 GHz frequency band.
SPU
Information Science Institute of Sripatum University
Standard: IEEE 802.11b –2.4GHz - 11 Mbps
802.11b enables transfers of up to 11 Mbps. Comparable to 10BaseT in speeds, 802.11b is the most common wireless standard deployed today. In comparison T1 speeds are 1.54Mbps and DSL is normally in the 640Kbps range.
Most deployments of Wireless utilize 802.11b
SPU
Information Science Institute of Sripatum University
Standard: IEEE 802.11.a – 5 GHz - 54 MbpsInternational standard for wireless networking that operates in the 5 GHz frequency range (5.725 GHz to 5.850 GHz) with a maximum 54 Mbps data transfer rate. The 5 GHz frequency band is not as crowded as the 2.4 GHz frequency, because the 802.11a specification offers more radio channels than the 802.11b. These additional channels can help avoid radio and microwave interference. Cost of 802.11a equipment is approximately twice that of 802.11b and current deployment is limited.
SPU
Information Science Institute of Sripatum University
StandardsIEEE 802.11.a –5GHz – 11Mbps
SPU
Information Science Institute of Sripatum University
Other Wireless Devices Bridges and Routers Print Servers
PCs, Laptops, PDAs
SPU
Information Science Institute of Sripatum University
Connecting To a Legacy Network
Access Points connect the wireless network to the legacy network.
SPU
Information Science Institute of Sripatum University
Why Deploy Wireless? Cost savings over wireline.
Can not run wire to locations needed.
To enable patrons to bring their own laptop, therefore reducing the cost of owning many PCs.
To enable you to easily move PCs.
To be on the leading edge.
SPU
Information Science Institute of Sripatum University
Environment Assessment Look at the structure of your building.
Steel, Concrete, Stone, GlassOpen w/ few walls or many separate
rooms?
Current technologies usedDo you use a 2.4 GHz cordless phone?
Does it work throughout your environment?
SPU
Information Science Institute of Sripatum University
Cost 802.11b Wireless Access Points start
around $130.00 for basic connectivity and run up to $500.00 for more management features.
802.11b Network Interface Cards (NICs) cost between $50-$100 and come in USB, PCI, PCMCIA and CompactFlash versions.
SPU
Information Science Institute of Sripatum University
The A-B-Gs of WirelessWhich standard is right for you? 802.11a
54 Mbps @ 5MHzNot widely adopted
802.11b11 Mbps @2.4GHzLow Cost
802.11gNew technology - Available late 2003Compatible with 802.11b
SPU
Information Science Institute of Sripatum University
22
SPU
Information Science Institute of Sripatum University
Bluetooth – 802.15 Bluetooth is the standard for wireless personal area networks or WPAN. It allows high speed transmission of data over very short distances. Bluetooth is normally used for transferring data between laptops, or in Internet Kiosk type applications where roaming is not needed.
SPU
Information Science Institute of Sripatum University
24
IEEE 802.16 (WiMAX)
SPU
Information Science Institute of Sripatum University
25
IEEE 802.16 (WiMAX)
SPU
Information Science Institute of Sripatum University
Partition The NetworkA safe practice is to create two separate
networks. A private network for day to day business and a network for public access. Both can be wireless. These networks can talk to one another through a proxy server that will protect the private network from malicious attacks via the public network.
SPU
Information Science Institute of Sripatum University
Encryption Encryption on the pubic network can be used but
would create administrative overhead. Encryption keys would have to be changed regularly and anyone using their own laptop would have to be given the key.
Encryption works best in a network that does not allow people to use their own laptops.
Encryption increases privacy, but can be thwarted, either by software, or by gaining access to a PC configured with wireless and writing down the key.
SPU
Information Science Institute of Sripatum University
Content Filtering & Proxy ServersWeb content filtering that has generally been
software on the desktop would have to be handled by a server if people are allowed to use their own laptops.
Proxy servers allow you to control what information people have access to. This is a good practice anyway, allowing you to control at a global level what information travels over your network. It also allows you to track usage.
SPU
Information Science Institute of Sripatum University