Understanding Systems Engineering Principles For Telecommunication Systems

Understanding the fundamental systems engineering principles and their applications in telecommunication systems.

a.Demonstrate in-depth knowledge of system engineering and understand how to make a system more reliable and efficient;

b.Acquire in-depth technical knowledge of signalling, switching and call routing in Public Switched Telephone Network (PSTN) and population queuing models;

c.Obtain conceptual knowledge and understanding of system reliability, maintainability, costing and design for affordability and human factors;

d.Demonstrate an in-depth understanding and knowledge of Digital Microwave Radio Systems;

e.Design Microwave links, path profile construction and acquire a comprehensive understanding of atmospheric effects on the performance of microwave links ;

The functions of a telecommunication network, whether it is wired or wireless, are specified by the size of its coverage area and traffic carrying capacity. On the other hand, the performance of the network is specified by its quality of service. Prepare a report containing the following points:

• Regarding PSTN exchange:

What limits the size of the coverage area of a PSTN telephone exchange?  

What limits the traffic carrying capacity of a PSTN telephone exchange?  

• Regarding mobile BTS station:

What limits the size of the coverage area of a mobile BTS station?  

What limits the traffic carrying capacity of a mobile BTS station?  

In-depth knowledge of system engineering

1. RELIABILITY

If the components are in parallel, system performs if any one component remains operational

 If there are n components in parallel, where the reliability of the i-th component is denoted by ri , the system reliability is

R_p=1-(1-r₁) (1-r₂)… (1-r_n)

For our case

Assume that the reliability of each subsystem (or component) i has the reliability of R_i. Calculate the reliability of the overall system R_S as a function of R_i.

R_S=1-(1-R_I) (1-R_I)

R_S=1-(1-R_I) ²

1. If the reliability of component i at time tis R_i (t) =e^-λit, what is the reliability function of the overall system at time t?

Q_i (t) = 1-e^-λit

 f (t) =   =   = λe ^-λit

1. Evaluate the mean time to failure (MTTF) of the overall system as a function of λ_iusing the reliability function in part (b).

Mean Time to Failure, MTTF= dt = 1/λ

=1/λ

1. Calculate the failure rate of the overall system with exponential reliability. Hint use binomial distribution.

Q_i (t) = 1-e^-λit

1. What is the mean time before failure (MTBF) of the above system?

= dt = 1/λ

Question 2 Digital Microwave Radio System

A point-to-point digital microwave radio system is required by a bank to link the LANs of two of its branches at 2.048 Mbps transmission speed. The handbook delivered by the manufacturer has dimensioned the entire radio terminal with the reliability: MTBF (mean time between failures): 100,000 hours  MTTR (mean time to repair): 2 hours (equipment only).  The radio path availability was calculated for =10^-8 and found to be 99.999% for the average worst case. The system configuration is shown in 

1. Calculate the overall system availability

Availability =MTBF/ (MTBF+MTTR)

=99.998%

1. Draw the reliability diagram of the system  
2. How would you increase the availability of the system required by the bank?  

FINDING AND IMPLIMENTING THE MEAN TIME TO REPAIR (MTTR)

Mean time to repair (MTTR) is the typical time necessary to deduce and mend failed equipment and return it to standard working settings [7]. It is an important procedural measure of the maintainability of apparatus and repairable parts. Preservation time is denoted as the time intermission between the beginnings of the event and when the system is returned to production. This encompasses of the notice time, analytical and problem-solving time, cool down time, reassembly, conformation, calibration, experiment time, back to production, etc. It regularly does not include lead-time for parts. Mean time to repair ultimately portrays how well a business can react to a mechanical itch and restore it.

1. The useful life of the equipment shown in Figure 2 is 15 years. Calculate the reliability of the one radio terminal at the end of it life.

Question 3 High Seed Connectivity

Access to the Internet has arguably become an essential service. However, the quality of the service varies widely in Australia. Multiple governments had promised (and begun to deliver) a high-speed connectivity throughout Australia via the NBN. Discuss and briefly explain the NBN technology. The discussion must be based on research findings, e.g. reference must be made of at least two journals.

The NBN (National Broadband Network) is an Australian local widespread open-access data connection project. It entails of both supported and radio communication devices revolved out and triggered by NBN Co Limited. Retail service providers (RSPs), usually Internet service suppliers, sign contract with NBN for the right to use the network and sell secure internet access to consumers [4]

Technical knowledge of signalling, switching, and call routing in PSTN and population queuing models

Advantages of NBN network

Stronger connections.
A quicker service means you are able to appreciate first-class video calls with distant friends and family, or dial into an imperative conference devoid of dropping out or freezing.

Smarter ways to work
 Home-based learning or working could get completely tranquil, with quicker entree to online gears and the aptitude to download and upload bulky attachments in a flash.

Better healthcare
A quicker service could mean that doctors and nurses are capable to conduct routine well-being consultations using teleconferencing and other online communication gears.

Improved economy

The national economy will benefit from faster broadband. Improved productivity. More remote work possible using thin clients and tele-cottage.

Cheaper and quicker business setup

Cloud computing will work with Australian clients. Multiple cloud data centres are in Australia.

Low telecommunication costs

NBN will lower telecommunication costs for business and home. Unlimited broadband on NBN is available. e.g. More streaming video, online education, multimedia production capacity.

Offer competitive advantage hence break monotony

NBN gives us a viable benefit in contradiction of other, less-connected, countries. It's a game changer that resolve several things might not have been planned.

NBN Disadvantages

Cost over runs, technical snafus, and just differences in opinion will be items of debate and discussion among voters.  This differs from private networks substantially where a much smaller number of stake holders make the decisions and have input while a network is being built [5].  

Longer term the upkeep of the network is likely to be more of a trial than a reserved network as most individuals undermine the functioning and repairs costs that go with administration of an access network.  This again is more complex for public networks because the NBN is just one more program that has to be deal with in the budget process [2].

Question 4 Functions of a Telecommunication Network

The functions of a telecommunication network, whether it is wired or wireless, are specified by the size of its coverage area and traffic carrying capacity. On the other hand, the performance of the network is specified by its quality of service. 

PSTN- is short form of public switched telephone network. Basically, it is the interconnected telephone system over which telephone calls are made via copper wires [8].

Size of the coverage area of a PSTN telephone exchange is limited by;

Telecommunication infrastructure-Inadequacy of deep-rooted infrastructure limits the coverage area.

Landscape/ Topography of the region- This affects line of sight for the conveyed signal. Therefore, coverage area is limited to LOS.  

Conceptual knowledge of system reliability, maintainability, costing, and design for affordability and human factors

Frequency in use- Higher frequency has less coverage compared to lower frequency used in PSTN.

Traffic carrying capacity of a PSTN telephone exchange is limited by;

Technology used- The technology cast-off, either GSM or UMTS controls the carrying capacity of PSTN as they vary in terms of capacity.

Transmission media- Lack of a highly carrying capacity media like fibre, limits traffic carrying capacity of the PSTN.

Equipment and devices used- use of low capacity/bandwidth devices to handle data give-and-take may limit the traffic volume handled by a PSTN.

Bandwidth- Large bandwidth put up high traffic carrying capacity as compared to low bandwidth.

Base Stations - Cell Coverage

The cell coverage range is deduced by the base station yield power and the surroundings. Obstacles such vegetation, mountains and structures have an impact on the area.

In metropolitan regions there is usually a greater quantity of operators and also impediments. To recompense, you find extra base locations to cater for the plea, and the cell dimensions have a 3-6km radius unlike in country areas with 10-32km radius [10].

Base Stations - Capacity

A base station can simply handle a definite quantity of calls at once. A distinctive base station has roughly 168 voice canals accessible and once capability is almost touched the base station will impeccably hand off a mobile operator to an alternative base station in the consumers’ range [9].

The base station similarly have a boundary to the extent of bandwidth accessible for internet and information use. With the introduction of android phones, the transferors intensify the network bandwidth and base stations to promise the internet does not turn out to be slow in the course of peak episodes. The broader the station bandwidth, the broader the pipe is to propel information. Standard network bandwidths used by the carriers in Australia are 11 MHz or 16 MHz. Vodafone anticipate on using 20MHz of bandwidth for 4G [10].

References

[1] Birolini, Alessandro. (2017). Reliability Engineering: Theory and Practice. Springer Verlag.

[2] Brown, Damien. “NBN Now 10 Times Faster.” The Mercury 13 Aug. 2010. ‹https://www.themercury.com.au/article/2010/08/13/165435_todays-news.html›.

[3] Carmines, E. G., & Zeller, R. A. (2008). Reliability and validity assessment. Newbury Park, Calif: Sage Publ. 

[4] Edwards, K., Rebecca G., Ratul M., and David W. (2010). “Advancing the State of Home Networking.” Communications of the ACM 54.6 .62-71.

[5] Neumann, K.-H. (2010). Structural models for NBN deployment. Bad Honnef: WIK Wissenschaftliches Institut fu [section] [u.a.

[6] Reliability Engineering Conference for the Electric Power Industry, & Institute of Electrical and Electronics Engineers. (n.d.). Reliability. New York: Institute of Electrical and Electronics Engineers.

[7] Tobias, P. A. (2012). Applied Reliability. CRC Press.

[8] Tucker, Rodney S. (2010). “Broadband Facts, Fiction and Urban Myths.” Telecommunications Journal of Australia 60.3: 43.1 to 43.15. 

[9] Wilken, R., Michael A., and Bjorn N. (2011). “Broadband in the Home Pilot Study: Suburban Hobart.” Telecommunications Journal of Australia 61.1: 5.1-16.

[10] Zafar, M. Shaqfeh, M.-S. Alouini, and H. Alnuweiri, “A suboptimal scheme for multi-user scheduling in Gaussian broadcast channels,” IEEE Trans. Signal Process., vol. 22, no. 2, pp. 136–140, Feb. 2015