Question $1$

$($a$)$ A city council is considering deploying hundreds of small button battery powered air

quality sensors around the city. Once an hour, the sensors would quantify the air quality

as being at one of five different levels and then transmit the sample over a radio link to a

central system where the information would be stored. The city would like to deploy the

sensor and not to have to worry about replacing the batteries for an extended time.

Give your opinion on whether it would be appropriate to use a source coding scheme in

such a case and explain what you think would be the most significant advantage of doing

so$.$

$[4$ marks$]$