You are working for a telephone company and you are asked to design a land-line

Question

You are working for a telephone company and you are asked to design a land-line network for a new residential area. The network is circuit switched. Since it is a new area, traffic statistics are not available. There are three approximations of the traffic rate: 30 calls/minute, 20 calls/minute, and 50 calls/minute. Each of the approximations has a probability of 0.3, 0.2 and 0.5, respectively. The duration of calls has an average of 3 minutes. (a) For the given rho, show a plot of the blocking probability as the number of circuits increase. (b) Design the number of circuits such that the blocking probability is 0.02 or less? (c) 10% of the circuits fail each year. Redesign the number of circuits such that the blocking probability would not exceed 0.03 even with circuits failure.

Explanation / Answer

Although there are all kinds of alternatives to a landline phone connection these days, from mobiles and smartphones to VoIP and video chats, landline phones have not given up the ghost entirely.

If you tend to text more than talk, need to be on the grid at all times, can't live without your mobile in your hand but still want to minimise the number of bills you're paying, kicking the landline to the kerb could be the way to go. However, if you do that, are you going to alienate family and friends – like your grandparents, for example – who may only be comfortable calling you on a landline? Are you comfortable with having no landline in the case of an emergency?

Landline advantages

Not surprisingly, Australia's two major landline service providers, Telstra and Optus, argue that landlines still play a vital role in the lives of many consumers. But their position is also backed by Australia's telecom regulator, the Australian Communications and Media Authority (ACMA).
According to Telstra, the top reasons to hold on to your landline include:

Generally, there are also those who want to keep a landline phone at home to maintain a communication option that parents and grandparents are more comfortable with – and to capitalise on the heavily discounted STD and international call rates most carriers now offer.

Cost and coverage issues

Some consumers might choose to keep a landline for voice calls if mobile coverage is limited where they live or work. This is particularly significant when dealing with networks that have blackout areas.

Telstra claims to provide mobile service to 99% of the population, but it's hard to substantiate. You can lose service to your mobile carrier for any number of reasons, including how many people are using the network at the same time. Andmobile pricing plans are still so complicated and variable that consumers often get hit with unexpected charges.

Alternatives to landlines

If you’d rather not rely solely on your mobile, but you're not happy with the ever-so-slightly antiquated idea of a home phone line, there are other alternatives that you might want to consider:

VoIP at home

VoIP (Voice over Internet Protocol) has proven a popular low-cost alternative to both mobile and landline phones for some homes. VoIP technology allows you to make voice calls over the internet using your PC or even through your own landline phone. Voice conversations travel through the internet as data packages and can connect with a landline or mobile phone. However, like mobile technologies, VoIP has also been rocked by reliability issues, and providers make no promises about being able to get through when you need to.

Despite some reliability issues over the years, VoIP services remain a critical low-cost component for many Australians' telecom packages and can be used with a VoIP phone, bundled with Naked DSL (broadband internet through your phone line with no phone rental cost), or used through a web-based application (like Skype) on a computer or smartphone. Some plans that combine Naked DSL with a VoIP service offer free national calls to landlines in addition to cheap calls overseas.

VoIP non-geographic numbers

VoIP services that receive a call from the Public Switched Telephone Network (PSTN) need a real telephone number to route calls correctly. However, some VoIP users have phone numbers that give no information of their geographic position as the number is based on an IP address rather than a fixed address.
For example, you may live in Sydney and move to Melbourne while keeping your Sydney phone number. This might be handy if most of the people you talk to live in Sydney and can call you for the cost of a local call. However, the downside is that it can be difficult to determine where the call originates from in case of an emergency. There have been examples of VoIP calls made where emergency services were sent to a completely different city due to the VoIP number used.

ACMA has raised these concerns and proposed amendments to the telecommunications determination for VoIP providers to only release geographically accurate phone numbers, or provide for an incoming call to be flagged as a VoIP number, so the caller will be asked for their location. The 0550 number range is used where the telephone service is not fixed to a particular location, such as a fully nomadic IP-based service.

VoIP on your mobile

Some people are making use of their mobile data plans to make calls rather than using their standard voice call allocation. Applications that make use of VoIP over a mobile network include the popular Skype app as well as Viber.
Skype is cheap, popular and easy to use, and it allows you to call regular phone numbers from the internet or phone app. If you want, you can also get a local Skype phone number for a small monthly fee, otherwise people can contact you through your Skype name via the app.
Viber is free, convenient and available for most platforms and operating systems, and free group calls are supported. But you can only call other people who are on Viber – through the app – and like Skype, you need to be online to use the service.
Apple's Facetime application is also an attractive option for Apple iPhone, iPad and iPod users who can call other Apple device owners for video and voice calls over a Wi-Fi network, and also over a phone network for some Apple devices.

Naked DSL

This option provides most of the advantages of a fixed broadband line without the monthly line rental charge, but it's also not as reliable as a fixed line. Naked DSL makes a landline internet connection possible without having to pay for telephone line rental. But beware: the ADSL still runs through the landline and activating it can be costly.

So, should I ditch my landline?

No matter how you slice it or dice it, a landline costs you $30 a month before you make a single phone call. The telcos may bury the cost in your overall plan but be assured, you are paying for your line rental.

Before deciding whether or not to ditch your landline once and for all, undertake a rigorous assessment of your telecommunications profile, including where you live, how many calls you make, and where you call. If you’re a fairly heavy user of your home phone – and reliability is important – keeping your landline may make good sense.

If you’re a habitual long-distance caller and have an internet connection, getting a handle on VoIP can save you money whether you keep your landline or not.

But if you're a light user who lives in a metropolitan area and rarely exceed your monthly mobile phone allowance, it could be time to cut the 'line.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.