NM-1.05

Question 1

How do we cope with the demand for higher capacity?

Answer 1

1. Radio link effiency
2. Spectrum -> increasing the BW
3. Topology -> more nodes in the wireless infrastructure; This is the best way. However, this is costly and might have interference issue if have too many.

Question 2

What is cell densification

Answer 2

Cell network -> dense network -> ultra-dense network; have more points of access than users

The BS is a lot more cheaper to implement and can implmenet more

Question 3

What’s the difference between HomNet vs HetNet

Answer 3

Homogenous Network

1. BS power -> 20w
2. Wifi -> 1W

Low power nodes; femtocells. We get closer to the users and reduce path loss.

Question 4

It seems that more nodes = higher throughput. Will it always be an advantage

Answer 4

No, due to interference. Watch out for diminishing returns

Throughput is upper bounded and we have intercell interference.

• Limited and fixed bandwidth
• Limited and fixed area

Question 5

Explain the interference in HetNet

Answer 5

See the interference in the transceiver

Question 6

What’s the difference between fixed and flexible reuse

Question 7

What is the range of frequencies in which 5G/mm Waves are being used?

Answer 7

28GHz = 300GHz

Question 8

What are the implications of MM wave spectrum

Question 9

What services that can be implemented because of MM wave on new 5G scenarios

Question 10

Which one among the following statements characterises Ultra Dense Networks

Answer 10

There are more BSs than UEs

Question 11

What is the difference between HomNet and HetNet

Answer 11

Homogenous Network (2G, 3G):
1. Uniformity; infastructure and technology are relatively uniform across the entire network

2. Coverage and capacity; designed for uniform coverage and capacity across all areas.

Approach works well in scenarios where there are similar requirements for all users or areas within the network.

Heterogeneous Network (4G, 5G);
1. Designed to optimise network performance in different areas based on varying requirements.

Question 12

What are the advantage of heterogeneous networks?

Answer 12

1. Improved coverage for cell-edge users (users or devices located at the outermost boundaries or edges of a cell’s coverage area).
2. Higher throughput (capacity to deliver high data rates to end-users)

Question 13

What are the issues with HetNet?

Answer 13

1. Performance degradation; cell-edge and network throughput
2. Inter-cell signalling overhead
3. Need for self-organisation

Question 14

Explain the difference between fixed and flexible reuse

Answer 14

IPAD

Question 15

What are the implications of mm wave spectrum?

Answer 15

1. Antennas are much smaller
2. Different propagation models