Question

a) Discuss the differences between cold handoff vs warm handoff in mobile communications.

b) Describe the use of picocells in mobile communication and discuss its benefits.

c) Discuss how 5G communications can achieve higher throughput than 4G.

Answer 1

a) Difference between Cold handoff Vs Warm handoff in mobile communication :-

Cold Handoff	Warm Handoff
i)  In a hard handoff or Cold Handoff, an actual break in the connection occurs while switching from one cell to another..	i) In soft handoff or Warm Handoff, at least one of the links is kept when radio links are added and removed to the mobile station.
ii) It is generally an inter-frequency handoff	ii) This is generally adopted in co-located sites
iii) It is a “break before make” policy.	iii) It is a “make before break” policy.
iv) Disturbance observe in this Handoff system	iv) No disturbance observe in this system.
v) At a time only one connection is present.	v) At a time two connection are present.
vi) In this communication build up less costly than Warm handoff.	vi) In this communication build up more costly than cold handoff.

b) Picocells :- Picocells are operated and managed more closely by the network operator who also pays for site rental, transmission back to the core network.it is a small mobile base station that improves in-building cellular coverage. This is the part of a small cell.Picocells are usually installed in larger indoor areas like shopping malls, workplaces and airport or stations they can accommodate up to 100 users at a time and ranges under 200 meters.picocells are generally installed by the network operators.A registered home user database in communication with the pico-cell for storing a list of user devices authorized to access the pico-cell and place the calls carried by the pico-cell. Advantages and benifits are -

i) Picocell antennas must have outdoor furniture assistance, high weather reliability and safe to touch design.

ii) The deployment of Picocell antennas are finding the cost effective and innovative solutions, optimizing signal coverage and avoiding interference.

iii) A call distributor in communication with the picocell for handling the calls carried by the pico-cell.

iv) An embedded wireless switch for routing the picocalls placed to and from the mobile devices in the building using the wireless protocol.

c) 5G is a new digital system for transforming bytes - data units - over air.It uses a 5G New Radio interface, along with other new technologies, that utilises much higher radio frequencies (28 ghz compared to 700 mhz - 2500 mhz for 4G) to transfer exponentially more data over the air for faster speeds, reduced congestion and lower latency, which is the delay before a transfer of data begins following an instruction.5G also uses a new digital technology called Massive MIMO, which stands for multiple input multiple output.

Compared to fourth generation mobile networking, 4G.One estimate suggests that 5G could use 90% less energy per bit than 4G.Energy consumption has a big impact on battery life for mobile devices. Three main components of fifth-generation technology standard for cellular networks: i) low-power cell sites ii) radio wave spectrums iii) a network backbone.

i) Network carriers install cell sites at strategic locations based on network usage rates and divide regions into sectors. With 5G, there could be a trend towards base stations that are more compact and use less power than typical 4G power base stations.

ii) Each cell site is connected to a network backbone, often through a wired fiber connection.

iii) Within these sectors, packets of data are sent between sites using either low-, mid-, or high-band frequencies.

Low-band frequencies typically operate below 2 GHz, mid-band sits between 2-10 GHz, and high-band enters the 20-100 GHz channels. Known as the “millimeter-wave” band, these previously unused frequencies are like data superhighways for latency-sensitive and bandwidth-intensive innovations. One challenge of high-band 5G is its short range, which requires more cell sites to be installed to ensure connectivity, in this cause 5G can achive more through output than 4G.