代做ELEC ENG 3108 Telecommunications Principles Assignment 1: Telephony代做Python语言

ELEC ENG 3108 Telecommunications Principles

Assignment 1: Telephony

Due 5pm on Monday 28 August 2023. This assignment is worth 20 or 30% of your final grade.

Submission is via MyUni.

What to submit

•    Your working and results

•    30% of your marks will be allocated to discussion, insight and original experimentation or

analysis. Your report is expected to be written to a professional standard and show original critical insight.

Question 1: Intelligent Network Implementation (20%)

A Vodafone pre-paid customer is about to initiate a phone call on the Vodafone GSM network to a friend on the Telstra GSM network.

•     Vodafone pre-paid services are handled by the Intelligent Network platform. Briefly list the major steps involved in setting up the call to the Telstra GSM network, assuming the customer has sufficient credit and the friend is available and answers.

•     Explain why pre-paid customers cannot (usually) roam, and suggest a mechanism by which pre-paid roaming could be achieved.

Vodafone’s pre-paid customers were previously handled by a Service Node. In this case, prepaid call traffic was routed through a separate switch, which would monitor calls and take action when credit was no longer available. 37% of Vodafone’s 2.2 million customers are now pre-paid, accounting for   25% of busy hour traffic (20 mErlang/subscriber).

•     If each MSC and pre-paid switch can handle 4,000 Erlangs of traffic, calculate the additional number of switches required to handle the current pre-paid customers using the Service

Node Architecture, versus using the Intelligent Network scheme

Question 2: Hata-Okumura Model (40%)

Find a reliable standards document written after 1998 which specifies which radio frequencies are specified for operating a GSM radio access network, and summarise the frequency bands.

Now consult the Australian Communications and Media Authority website to identify how these bands are allocated and whether they are currently configured for GSM. Summarise your findings.

Create a function (Matlab, Excel, Python – your choice) which implements the Hata-Okumura model. Explore the path loss behaviour of the uplink and downlink spectrum bands, against a range of antenna heights (base station and mobile station).

Your function, or functions, should determine the path loss at a given distance, and maximum coverage distance given a link budget.

Question 3: GSM Network Dimensioning (40%)

GSM-R is a variant of the popular GSM standard with specific changes to accommodate the needs of communication for railway  operations. The only difference of interest in this question is that GSM-R may operate at radio frequencies outside the spectrum normally allocated for public telephone services.

Your task is to prepare a radio network plan for a railway network consisting of:

•    A metropolitan area of 1000 km2  which requires extensive coverage.

•    4000 km of railway track in country areas in a roughly circular layout. There are 150 country towns which are spaced between 15km and 30km apart along the track. There is no requirement for area coverage in the country.

Radio standard:

•     FDMA carriers of bandwidth 200kHz.

•    8 timeslots per FDMA carrier

•    Only one common channel is required per sector.

•     Frequency reuse plan:  3/9 with no overlay for the metropolitan area only

•     In the country areas, a cell reuse distance equal to the coverage distance of three

intermediate cells is required. Each country base station consists of two long-distance high gain antennas, pointing along the railway line.

Coverage characteristics

•    Very uniform. flat urban city

•    Country areas are mountainous and path loss should be assumed to be equivalent to an urban city.

•    Antenna height is fixed at 30m in the city and 200m for all country areas

•     In the city, there are 200 trains.  Each train generates 3.0 erlangs of traffic.  All trains are running between 5pm and 6pm.

•     In the country, there are a total of 10 trains.  Each train generates a total of 1.0 erlangs of traffic.  98% of the time, no more than 2 trains are within 35km of each other.

Grade of Service of 2% with mobility derating factor 2.2 in the city only.

	City Base Station	Country Base Station	Mobile Station
Transmitter
Transmission power (includes losses)	125W	150W	8W
Antenna Gain	13dBi	17dBi	0dBi
Receiver
Minimum Receive Power (does not include antenna gain)	-100dBm	-100dBm	-100dBm
Antenna Gain	13dBi	17dBi	0dBi
Shadow Margin	10dB	10dB	10dB

You have the following choices of radio frequencies, as specified in the GSM standard. Determine which spectrum band is the most suitable for the entire network (you might need to answer this question after considering the following questions considering both options):

i.            450MHz band (paired 3.6MHz available)

•      Downlink 460.5MHz-464.1MHz

•      Uplink 450.5MHz-454.1MHz

ii.           850MHz band (paired 10.8MHz available)

•      Downlink 869.1MHz-879.9MHz

•      Uplink 824.1MHz-834.9MHz

Using the Hata path loss model, calculate the maximum coverage distance in the city and the country. Assume a(hm) = 0 and be sure to justify why the uplink determines the cell size.

Hence, calculate how many base stations are required for coverage of the rural railway tracks.

Is it necessary to consider capacity in country areas?  Explain your answer

Calculate how many base stations are required for coverage of the city

Calculate the number of traffic channels available per cell in the city, assuming all available spectrum is uniformly utilised.

Hence, determine the number of base stations required in the city area for capacity.