wlan and bluetooth

Last updated on Dec 12, 2023

1. Physical Layer:

Frequency Bands: WLAN operates in the 2.4 GHz and 5 GHz frequency bands. 802.11ax (Wi-Fi 6) can also use the 6 GHz band.
Modulation Techniques: Common modulation schemes include QPSK, 16-QAM, and 64-QAM.

2. Data Link Layer:

Multiple Standards: The IEEE 802.11 family of standards is widely used for WLAN. Common standards include 802.11a, 802.11b, 802.11g, 802.11n, 802.11ac, and 802.11ax.
Frame Structure: WLAN uses frames for communication, including management frames (e.g., association, authentication), control frames (e.g., ACK), and data frames.

3. MAC Layer (Medium Access Control):

CSMA/CA: Carrier Sense Multiple Access with Collision Avoidance is the protocol used to manage access to the wireless medium.
Authentication and Association: Devices must authenticate and associate with an access point before communication.

4. Network Layer:

IP Protocols: WLAN typically operates at the data link layer, and IP is used at the network layer. IP addresses are assigned to devices.

5. Security:

Encryption: WPA2 (Wi-Fi Protected Access 2) and WPA3 provide encryption for securing wireless communication.
Authentication: Pre-shared keys or enterprise-level authentication methods are used.

6. Mobility:

Roaming: WLAN supports seamless roaming between access points within the same network.

1. Physical Layer:

Frequency Band: Bluetooth operates in the 2.4 GHz ISM band.
Modulation Techniques: Bluetooth uses various modulation schemes, including GFSK (Gaussian Frequency Shift Keying).

2. Data Link Layer:

Bluetooth Versions: Bluetooth has gone through multiple versions, with Bluetooth 4.0 (Bluetooth Low Energy, BLE) and Bluetooth 5 being the most recent as of my knowledge cutoff in 2022.
Frame Structure: Bluetooth uses packets for communication, including advertising packets, data packets, and acknowledgment packets.

3. MAC Layer (Medium Access Control):

Frequency Hopping: Bluetooth uses FHSS (Frequency Hopping Spread Spectrum) for channel access, hopping between 79 different channels.
Connection Establishment: Bluetooth devices go through a process of inquiry, paging, and connection establishment.

4. Network Layer:

Profiles: Bluetooth devices use specific profiles (e.g., Hands-Free Profile, A2DP for audio streaming) to define how they communicate with each other.

5. Security:

Pairing: Devices establish a secure connection through a pairing process, which can involve passkeys, PINs, or other authentication methods.
Encryption: Data exchanged between paired devices is encrypted to ensure privacy.

6. Connectivity:

Piconet and Scatternet: Bluetooth devices form piconets, and multiple piconets can be connected to form a scatternet, allowing more complex network topologies.