WN - 2.03

Question 1

What is spectrum sharing

Question 2

Give the frequency band for road transport and traffic telematics

Answer 2

403, 433, 865 MHz

Question 3

Give the frequency band for intelligent transport systems

Answer 3

2.4, 5 GHz

Question 4

What are the benefits of unlicensed

Answer 4

1. Facilitating market entry - no need to acquire a license to deploy a service
2. Reduced congestion in licensed bands
3. Ability to extend the reach of fixed communication networks, by providing wireless local area aconnectivity in homes etc.

Question 5

What are the benefits of unlicensed bands for end-users

Answer 5

1. Greater convenience and flexibility by avoiding the need for lengthy runs of cable in home and work environments.
2. Enhanced convenience -> safety and security

3.

Question 6

WIFI is based on what series of standards

Answer 6

IEEE 802.11 series of standards

Question 7

What is a key feature of the 802.11 standards

Answer 7

CSMA/CA interference

Question 8

When discussing WIFI, why do we also think of 5G

Answer 8

If 5G wants to use this spectrum it must also abide by the rules applicable to WIFI

Question 9

What is 802.11n variant

Answer 9

Single or dual band

• Enhancements such as MIMO antennas
• wider 40 MHz channels
• air bit rate 600 Mbps

Question 10

What is 802.11a variant

Answer 10

• 80/160 MHz
• higher modulation (256 QAM)
• over-the-air bit rate - 1 Gbps

Question 11

What is 802.11ah variant

Answer 11

1. For M2M and low bit rate applications
2. May be used coverage of broadband WiFi -> sub-1 GHz spectrum
3. Bandwidth options of 1, 2, 4, 8, 16 MHz

Question 12

What is 802.11ad variant

Answer 12

1. Wi_Gig
2. 60 GHz mm wave band
3. very high-speed, short-range applications
4. applications -> simultaneous streaming, instant data synchronisation

GOAL: deliver multi-Gigabit speeds with very low latency

7 Gbps over ranges of up to 10 metres

Question 13

What is 802.11ay variant

Answer 13

1. Aims of data rates in excess of 30 Gbps
2. Potential applications -> LOS wireless backhaul
3. e.g. enabling a full-length movie to be downloaded in under a second.

Question 14

Which one among the following bands is the most
relevant in the context of cognitive radio
systems coexistence with radar systems?

❑ 400 MHz
❑ 3.5 GHz
❑ 60 GHz

Answer 14

3.5 GHz,