This document provides an overview of wireless communication and networking. It defines wireless communication and discusses wireless network topologies and integration with wired networks. It describes the IEEE 802.11 wireless standards including 802.11a, 802.11b, 802.11g and 802.11n. It also discusses wireless networking devices such as access points, wireless LAN controllers, and bridges. Finally, it covers common wireless security measures including SSID hiding, MAC address filtering, static IP addressing, 802.1X authentication, WEP, WPA, and WPA2 encryption.

1. Wireless Communication and
Networking
.

2. Presentation Outline
Wireless Communications
Wireless Technology overview
The IEEE 802.11 WLAN Standards
Secure Wireless LANs
Migrating to Wireless LANs (Cutting the cord)

3. WIRELESS
Any type of electrical or electronic operation without use of wires
Wireless connections use air to connect sending and receiving devices
Channel is a division in transmission medium

4. COMMUNICATION
It is transmission of signals i.e. sending of electromagnetic waves by electronic
transmitters

5. WIRELESS COMMUNICATION
Communication networks are generally implemented with some type of remote
information transmission system that uses electromagnetic waves.
Wireless communication may be via:
Radio frequency communication
Microwave communication
Infrared short range communication

6. Types of Networks
LAN – Local Area Network
MAN – Metropolitan Area Network
WAN – Wide Area Network
GSM – Global System for Mobile Communications
PCS – Personal Communication Services
Wi-Fi – Wireless Fidelity
GPRS – General Packet Radio Service
AMPS- Advanced Mobile Phone System

7. Wireless Network
What is a wireless network?
◦ A technology that enables two or more entities to communicate without
network cabling

8. Common Topologies
The wireless LAN connects to a wired LAN
There is a need of an access point that bridges wireless LAN traffic into the
wired LAN.
The access point (AP) can also act as a repeater for wireless nodes, effectively
doubling the maximum possible distance between nodes.

9. Common Topologies
Complete Wireless Networks
The physical size of the network is determined by the maximum reliable
propagation range of the radio signals.
Referred to as ad hoc networks
Are self-organizing networks without any centralized control
Suited for temporary situations such as meetings and conferences.

10. How do wireless LANs work?
Wireless LANs operate in almost the same way as
wired LANs, using the same networking protocols
and supporting the most of the same
applications.

11. How are WLANs Different?
They use specialized physical and data link protocols
They integrate into existing networks through access points which
provide a bridging function
They let you stay connected as you roam from one coverage area to
another
They have unique security considerations
They require different hardware
They offer performance that differs from wired LANs.

12. Physical and Data Link Layers
Physical Layer:
The wireless NIC takes frames of data from the link layer, scrambles the data in a
predetermined way, then uses the modified data stream to modulate a radio
carrier signal.
Data Link Layer:
Uses Carriers-Sense-Multiple-Access with Collision Avoidance (CSMA/CA).

13. Integration With Existing Networks
Wireless Access Points (APs) - a small device that bridges wireless traffic to your
network.
Most access points bridge wireless LANs into Ethernet networks.

14. Integration With Existing Networks

15. Roaming
Users maintain a continuous connection as they roam from one physical area
to another
Mobile nodes automatically register with the new access point.
Methods: DHCP, Mobile IP
IEEE 802.11 standard does not
address roaming, you may need
to purchase equipment from one
vendor if your users need to roam
from one access point to another.

16. What is 802.11?
A family of wireless LAN (WLAN) specifications developed by a
working group at the Institute of Electrical and Electronic Engineers
(IEEE)
Defines standard for WLANs using the following four technologies
Frequency Hopping Spread Spectrum
Direct Sequence Spread Spectrum
Infrared
Orthogonal Frequency Division Multiplexing
Versions: 802.11a, 802.11b, 802.11g, 802.11n

17. WIFI Standard..
802.11a
offers speeds with a theoretically maximum rate of 54Mbps in the 5 GHz band
Pros of 802.11a - fast maximum speed; regulated frequencies prevent signal interference
from other devices
Cons of 802.11a - highest cost; shorter range signal that is more easily obstructed
802.11b July 1999
offers speeds with a theoretically maximum rate of 11Mbps at in the 2.4 GHz spectrum band
Pros of 802.11b - lowest cost; signal range is good and not easily obstructed
Cons of 802.11b - slowest maximum speed; home appliances may interfere on the
unregulated frequency band

18. WIFI Standard..
802.11g 2002 and 2003
is a new standard for data rates of up to a theoretical maximum of 54 Mbps at 2.4 GHz.
Pros of 802.11g - fast maximum speed; signal range is good and not easily obstructed
Cons of 802.11g - costs more than 802.11b; appliances may interfere on the unregulated
signal frequency
802.11n (Recently)
Specifications providing for up to 300 Mbps of network bandwidth. 802.11n also offers
somewhat better range over earlier Wi-Fi standards due to its increased signal intensity
MIMO technology(Multiple Input Multiple output) MESH

19. WIFI Standard
Pros of 802.11n - fastest maximum speed and best signal range; more resistant to signal
interference from outside sources
Cons of 802.11n - standard is not yet finalized; costs more than 802.11g.

20. Operating Frequency
2.4 GHz
Indoor AP(Access Point) operate 2.4GHz due good penetration power.
5 GHz
Outdoor AP(Access Point) operate on 5GHz for maximum coverage.
Problem. If we have to install more than One AP at a single location what about
the Frequency interference?

21. Frequency Channel
Division of Frequency
To Avoid from interference we use non-overlapping frequency channel of same
frequency band
(Band 2.4GHz , 5.0 GHz)
Different Devices Support different number of frequency channel.

22. 2.4GHZ Channel
CHANNEL NUMBER LOWER FREQUENCY
MHZ
CENTER FREQUENCY
MHZ
UPPER FREQUENCY
MHZ
1 2401 2412 2423
2 2404 2417 2428
3 2411 2422 2433
4 2416 2427 2438
5 2421 2432 2443
6 2426 2437 2448
7 2431 2442 2453
8 2436 2447 2458
9 2441 2452 2463
10 2451 2457 2468
11 2451 2462 2473
12 2456 2467 2478
13 2461 2472 2483
14 2473 2484 2495

23. Non-overlapping Frequency Channel…

24. Non-overlapping Frequency Channel

25. Wireless Networking Devices
AP
WLC (WIRELESS LAN CONTROLLER)
CPI (CISCO PRIME INRESTRUCTRE)
BRIDGE

26. AP (ACCESS POINT)
Is a device that allows wireless devices to connect to a wired network using Wi-Fi, or
related standards. The AP usually connects to a router (via a wired network) as a
standalone device, but it can also be an integral component of the router itself. AP emit
the signal called SSID(Service Set Identifier).
AP ROLE
RAP (special scenario)
MAP (Special scenario)
Client
Repeater

27. RAP (Remote Access Point)
Provide up link to it’s nearest AP
RAP is connected via Bridge to the NOC (network operation Center)
RAP also provide the services to end client

28. MAP (Mesh Access Point)
Get uplink from RAP.
Provide services to end user
CLIENT
Single AP ,decently connected with network switch.
Bridge
A Bridge is used to provide uplink to a remote AP via Wireless
Repeater/Booster
Repeater and Booster are used to amplify the Signal on the behalf of other AP

29. WLC (Wireless LAN Controller)…
Assign the role of RAP & MAP
Control the traffic of Wireless Device
Auto Shifting of RAP (Incase Parent RAP is down)
Has ability to differentiate between Voice and DATA
Traditional roles of access points, such as association or authentication of wireless clients, are
done by the WLC
CAPWAP (Controlling and provisioning of wireless AP) IOS of WLC
CAPWAP is used to communicate between the controller and other lightweight access points
on the network

30. WLC (Wireless LAN Controller)
All the client (802.11) packets are encapsulated in a LWAPP packet by the AP and sent to the
WLC.

31. Security Measures
SSID hiding
A simple but ineffective method to attempt to secure a wireless network is to hide
the SSID (Service Set Identifier).This provides very little protection against anything but the most
casual intrusion efforts.
MAC ID filtering
One of the simplest techniques is to only allow access from known, pre-approved MAC
addresses. Most wireless access points contain some type of MAC ID filtering. However, an
attacker can simply sniff the MAC address of an authorized client and spoof this addresses.
Static IP addressing
Typical wireless access points provide IP addresses to clients via DHCP. Requiring clients to set
their own addresses makes it more difficult for a casual or unsophisticated intruder to log onto
the network, but provides little protection against a sophisticated attacker

32. 802.11 security
IEEE 802.1X is the IEEE Standard Authentication mechanisms to devices wishing to attach to a
Wireless LAN.
WEP (Wired Equivalent Privacy)
The 64-bit WEP data encryption method allows for a five-character (40-bit) input. Additionally,
24 factory-set bits are added to the forty-bit input to generate a 64-bit encryption key. data
encryption method allows for a five-character (40-bit) input. Additionally, 24 factory-set bits are
added to the forty-bit input to generate a 64-bit encryption key.
WPAv1 (Wi-Fi Protected Access)
The Wi-Fi Protected Access (WPA and WPA2) security protocols were later created to address
the problems with WEP.WAP and WAP2 support up to 14 character.

33. M Sabir Saeed
ICT-TRAININGG
ICT-INTEGRATORS
LAHORE PAKISTAN