Week 3

Question 1

What is Access points?

Answer 1

Support internet roaming
Time synchronisation
Power management

Question 2

What is DS and AP, and state its relationship

Answer 2

DS=Distribution system
AP= access point
The DS provides the wired backbone that connects APs and forwards traffic, while APs provide wireless access to that network, enabling roaming and internet connectivity for users

Question 3

What is BSSID and SSID, what is the difference and relationship

Answer 3

BSSID= Basic service set identifier
SSID= Service set identifier
The difference lies in BSSID the MAC address of specific Access Point
while SSID is universal MAC address

Question 4

Explain Passive and active scanning, and its relationship

Answer 4

Both scanning methods is used by access points to share user information.
In passive scanning, client listens silently on WIFI and wait for become frames to be sent.
In active scanning, client send probes on all channels and wait for other ap response.
Both scanning methods are used by clients (e.g., phones, laptops) to discover Wi-Fi networks.
APs respond (in active scanning) or broadcast regularly (in passive scanning), but they don’t scan.

Question 5

How does network connectivity is establised

Answer 5

1. Scanning of network
2. Pre-association, discovery phase, let client decide network
3. Authentication, Client send authentication request to AP
4. Association, Send associated request to AP, get response then establish network traffic

Question 6

How do users typically break connection between a network

Answer 6

User would send a disassociation or deauthentication frame.

Question 7

How do network create a seamless connectivity

Answer 7

1. Reassociation request will be sent to target AP
2. Acknowledgement Frame is sent from target AP
3. Target AP request for client information from previous AP
4. Previous AP sent client info back to Tartget AP
5. Target AP sent reassociation response to user
6. User acknowledge response, ACK

Question 8

Type of mode available in access point

Answer 8

1. Root mode (share distribution system)
2. Bridge mode (intersect network)
3. Repeater mode (Repeat network from root) (50 percent share connection radius)

Question 9

Explain Roaming

Answer 9

Basically happens when client move from one AP to target AP
1. Reassociation request
2. Reassociation response
3. Handoff request and response
4. Delivery frames to user
5. Data traffic

Question 10

Explain WLAN design

Answer 10

1. Coverage design
2. Capacity design
3. Roaming design
4. Channel design

Question 11

How to maintain good quality network?

Answer 11

1. Signal to noise ratio
2. Dynamic rate switching
3. Transmit power
4. Reduce transmit power to increase performance