Telecommunication System Engineering (ME503) Assignment 1 Report

This report, prepared for the ME503 Telecommunication System Engineering course, delves into two key areas: Private Branch Exchange (PBX) systems and high-speed connectivity, particularly the National Broadband Network (NBN) in Australia. The PBX section explores the evolution of PBX, from manual switchboards to modern IP and hybrid systems, analyzing their architecture, components, and a comparative cost analysis of digital, on-site IP, hybrid, and cloud-based PBX systems. The high-speed connectivity segment focuses on NBN technology, detailing its wired and wireless communication methods, including fibre to the node (FTTN), fibre to the premises (FTTP), hybrid fibre-coaxial (HFC), fibre to the curb (FTTC), fixed wireless, and satellite services. The report also includes a comparison of NBN technology with similar internet infrastructure in New Zealand. The report is well-structured, providing a clear understanding of the telecommunication systems.

TELECOMMUNICATION SYSTEM ENGINEERING
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Table of Contents
Part A - Telecommunications Technologies...........................................................................................2
Q1. Private Branch Exchange (PBX).......................................................................................................2
Q2. High Speed Connectivity.................................................................................................................4
References.............................................................................................................................................5
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Part A - Telecommunications Technologies
Q1. Private Branch Exchange (PBX)
Introduction
Private Branch Exchange or PBX is a phone system within an organisation that enables the inter-
communication within an organisation through the telephones installed within the organisation. This
is a cost-saving system of telephonic connection since the system eliminates the need for any
external phone lines.
a) Evolution of PBX
The system of Private Branch Exchange was introduced in 1978[1]. Before the introduction of the PBX,
a similar manual console or switchboard developed shortly after Alexander Graham Bell’s model of
the telephone was used to switch calls within the organisation, making it the first rough model of the
present PBX. This model of the switchboard was predominantly used until the Great Depression
where departments within an organisation increased in number, making it difficult for manual
operators to switch calls to the concerned person. This resulted in the developed and more
mechanical form of the PBX to come into existence in 1972. This development eliminated the need
for manual operators [2].
b) Comprehensive analysis of current and emerging PBX systems in terms of reliability
The most prevalent and widely used PBX system in existence at the moment is the TDM system.
TDM refers to the system of Time Division Multiplexing, which allowed multiple strains of
information to be conveyed through one path. In the current times, TDM is the most widely used
system in order to sample multiple incoming voice and data signals, enabling these samples over
single transmission channels for the purpose of reconstruction for the purpose of the receiver. Apart
from TDM, IP PBX and Hybrid PBX systems have also come into prevalence. IP PBX enabled the more
advanced forms of communication to be conveyed through the phones. This is the initial form of the
modern IP addresses that every single device has that uses the internet. Hybrid PBX is another form
of the modern PBX where the traditional PBX and the IP PBX were mixed together. This was a
preferable choice for those who trusted the PBX systems but were afraid to use the new technology
of the IP PBX.
c) Architecture of PBX Systems
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The main components for a basic IP PBX system are a SIP server, Conference Server, Media Server,
PSTN Gateway, Unified Messaging and a protocol converter [3]. The SIP Server is a proxy server, used
as a redirect and registration server. Conference server or the SIPConf is a server that enables
centralised audio and video conferencing. Media server enables the streaming of media, generally
used for the storage and delivery of announcements. The PTSN gateway is connected to the central
PBX and the LAN of the organisation. Unified messaging refers to the machines with inbuilt storage,
used for the purpose of recording voice messages and as a central answering machine. The Protocol
Converter is a basic necessity for multimedia conferencing.
d) Comparison and contrast of different PBX systems in terms of costing
There are four main types of PBX systems - the digital PBX system, the on-site IP PBX system, the
hybrid PBX system and the cloud-based PBX system [4].
The Digital PBX System
Digital PBX systems are a more integrated and developed form of PBX systems. Including features
like adding music for customers on hold, this system offers functions like extensions and transfers.
This is a preferred system for businesses still used to the older method of PBX systems, with old
wirings and unreliable internet connections.
On-Site IP PBX System
This PBX system is more often known as the Voice IP or VoIP. This system of PBX uses the existing
internet connection available in order to provide both phone service as well as unified
communications. Due to the various advantages of better sound quality, call stability and the more
advanced applications of the PBX system, this system is one of the most widely used PBX systems [5].
Hybrid PBX System
This system is a hybrid of the digital and on-site PBX systems. This system provides the added benefit
of excellent voice quality during calls and conferences. Organisations that prefer to have their lines
on site generally prefer to use this system over others.
Cloud-Based PBX System
The cloud-based PBX system provides all the features, applications and services through cloud
services. Since the services and features are available on the cloud, therefore the cost for this system
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is also billed in one invoice, helping to reduce costs. Apart from reducing cost, this system also
reduces the constant concern of software update and maintenance.
The analysis of the four kinds of PBX systems has revealed that the cloud-based PBX system is the
most cost-effective and cost-reducing PBX system out of the four. Due to the easy availability of the
best features, this system is preferable for those looking for cost management within inter-
organisational communication [6].
Q2. High Speed Connectivity
Introduction
High speed connectivity is referred to as the internet connectivity speed that enables downloading
content at the speed of at least 25 megabits per second. In Australia, National Broadband Network
or NBN is a major provider of internet and phone services [8].
a) NBN Technology
The latest NBN technology includes wired communication through copper, optical and hybrid fibre-
coaxial wires. The Network also provides radio communication services and internet services
through satellite and wireless network through a number of Points of Interconnect (POI) located
throughout Australia [8].
Wired communication is provided through the means of fibre to the node (FTTN), fibre to the
premises (FTTP), and hybrid fibre-coaxial (HFC) and fibre to the curb (FTTC). Latest technology in
Radio communication is also provided in the form of fixed wireless networks and
telecommunications satellites [9].
b) Comparison of NBN with similar technology used in New Zealand
There are a lot of companies that provide internet services in New Zealand. Similar to NBN, the
GPON technology, or the Gigabit-capable Passive Optical Network, provides internet through
copper, optical and hybrid fibre-coaxial fibres. Additionally, Vodafone provides fixed wireless
services over LTE to the rural population [10].
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References
[1] Mizumoto, M. and Kataoka, M., Panasonic Intellectual Property Management Co Ltd, 2016.
Private branch exchange. U.S. Patent Application 15/040,673.
[2] Bebusinessed.com (2019). History of PBX.Available at: https://bebusinessed.com/history/history-
of-pbx/
[3] Citeseerx.ist.psu.edu (2019). IP PBX: Architecture and Protocols. Available at:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.671.7110&rep=rep1&type=pdf
[4] Ostergaard, P.F.N. and Wilson, D.A., Norwood Systems Pty Ltd, 2017. Method and device for
configuring a communication system.U.S. Patent 9,723,537.
[5] Tagg, J.P. and McEwan, A.D., Truphone Limited, 2015. System for providing mobile VoIP.U.S.
Patent 9,049,042.
[6] Xenexsystems.com.au (2019). What are the different types of PBX systems? Available at:
https://xenexsystems.com.au/blog/what-are-the-different-types-of-pbx-systems/
[7] Magee, L., Neilson, B., Third, A., James, P., Stone, G., Keltie, E., Thomson, R.J., Bhatia, S. and
Huang, Q.R., 2017. Gen nbn™: 2020 and Beyond: The Future of a Connected Australia.
[8] Nbnco.com.au (2019). Nbn Fixed Line Connections. Available at:
https://www.nbnco.com.au/residential/learn/network-technology
[9] Nbnco.com.au (2019). National Broadband Network, Australia. Available at:
https://www.nbnco.com.au/
[10] Export.gov (2018). New Zealand ICT.Available at: https://www.export.gov/article?id=New-
Zealand-information-and-communications-technology
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