Question

Which among the following combination of layers can be used to improve blockage control?

(a) Physical-Datalink

(b) Datalink – network

(c) Physical-Transport layer

(d) Datalink- Transport layer

I have been asked this question in a job interview.

I'd like to ask this question from Next Generation Wireless Network topic in section Next Generation Wireless Network of Cognitive Radio

Answer 1

The correct answer is:

(b) Datalink – network

Explanation:

In the context of blockage control in wireless networks, especially in cognitive radio and next-generation wireless networks, the Datalink and Network layers are the most relevant combination for managing and improving blockage control. Here's why:

• Blockage control refers to techniques used to manage signal degradation or loss due to physical obstructions (like buildings, trees, or other environmental factors) that can block or interfere with the transmission of signals in wireless networks. To deal with such issues effectively, multiple layers of the communication stack can be involved.

• Datalink layer: This layer handles access to the physical medium and manages errors in data transmission. It can play a role in detecting and mitigating the effects of blockage by using retransmission schemes, error correction, or adaptive techniques to maintain communication despite blockages.

• Network layer: This layer is responsible for routing packets between devices in a network. In the context of blockage control, the network layer can assist by dynamically selecting alternative routes or paths for data transmission to avoid areas with significant blockage. It can take into account the availability of paths and adapt routing based on environmental factors such as signal quality or interference levels caused by obstructions.

By combining the Datalink layer, which manages local transmission reliability, with the Network layer, which can choose optimal routes based on network conditions, this combination provides a comprehensive approach to manage and mitigate the impact of blockage in wireless communication.