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Shirley Stevens asked:


With the wide choice of fast broadband deals now available, there is no longer any need to struggle along at a snail’s pace, regardless of what you are trying to download. You’ll be absolutely amazed at the opportunities opening up for you around the internet.

Why is it worth taking a fast broadband package?

Fast broadband speed allows data to be transferred at a breathtaking speed, meaning no more frustrating waiting around for downloads or annoyingly missing out on game patches.

You should seriously think about faster speeds if you are a frequent downloader of movies or music, or even large files.

Online gamers stand to gain the most as the latency and ping times experienced are vital milliseconds lower, giving one that extra advantage over your opponent.

How fast is fast?

A 512kb connection was considered fast broadband a few years ago, but the newer fastest broadband packages are regarded as those above the average ‘up to’ 8Mb ADSL connection and use either fibre optic cable or ADSL2+ technology.

The highest download speed available on your broadband connection is measured in Megabits per second (Mbps), with latest technologies capable of providing broadband connections of ‘up to’ 24Mb per second.

It has been estimated that before the end of this year speeds of 50Mb will be reached, or up to as much as 200Mb employing the same technology.

How does one choose fast broadband?

It’s important to remember that the ideal fast broadband provider is one which allows you unlimited download with no restrictive fair use policy to trip you up.

Here, you will find Be Broadband particularly lenient regarding peak time usage. Virgin Media has a traffic management policy, which means that you need to watch your peak time usage carefully.

If you exceed your allowance, Virgin Media will temporarily slow down your fast broadband connection and that would just be infuriating.

Another option worth thinking about is ADSL2+ providers, with their higher upload speeds of around 256Kb.

Be Broadband and O2 Broadband are two providers which offer even faster upload speeds up to about 1.3Mb.

While upload speeds are not of much use to the average web user, gamers, home office workers and file sharers will appreciate the added oomph of a faster upload speed.

A site that allows you to compare broadband deals by speed, will help make your choice for broadband speeds much easier.

Is my area enabled for fast broadband?

Not every BT exchange in the country is enabled for fast broadband and some broadband services are restricted to particular areas. Many broadband providers have in fact installed their own equipment in various local exchanges to be able to provide such high speeds.

It is advisable to check which services you are able to receive in your area with a postcode checker.

Abha Duhring asked:


s are portable systems, it is very essential that the laptops must be placed in secure and safe laptop cases. Huge varieties of laptop cases are widely available in the market such as the leather laptop cases, aluminum laptop cases and feminine laptop cases exclusively for women.

The waterproof laptop cases

Waterproof laptop cases are counted best among other laptop cases. At times, the users who extensively commute might get caught in snow or rain and in such situations the waterproof laptop cases significantly protects the device from nay kind of damage. Even at office or home, it is possible that water or any other form of liquid might come in contact with the device and can impair your laptop, thus, to avert damage it is very essential to secure the laptop from water by using the waterproof laptop cases. The waterproof laptop cases are normally made from plastic that being highly water resistant is an ideal material for the waterproof cases. A waterproof laptop case protects laptops not only from water or moisture but also from scratches, dust, shock, damages, corrosion and heat.

The waterproof laptop cases have padded compartments so that the user can easily keep various other things as well such as binders, diskettes, lose files, business cards and pens. Also, few varieties of the laptop cases are equipped with an unseen telescopic handle or ergonomic handle. Majority of the waterproof laptop cases come with quick release straps and an integrated lock system. In addition, some laptop cases manufacturers have also introduced waterproof laptop cases with customizable fit. At the time of choosing the appropriate waterproof laptop case, the foremost thing to be considered is the size of the laptop so that the device could fit in snugly and easily. A laptop is a very delicate electronic device and has a huge risk of being damaged when transported.

So, those people who travel a lot and carry along various other things such as loose documents, binders and various other things to carry along, should certainly invest in the waterproof laptop cases as no one is sure what kind of weather you may get where you are traveling. One can buy the waterproof laptop case that has wheels attached to it or the laptop case with shoulder straps. If you are buying a waterproof laptop case make sure it is made out durable quality and has guarantee period in case of any production faults. There are various cheap laptop cases available in the market but such covers do not provide extra padded compartments, have a short life and may not fulfill the purpose of protection against water effectively.

Apart the cheap waterproof laptop cases, and discount waterproof laptop cases are also accessible in the market. These laptop cases come in various sizes, shapes, styles and designs and can be picked accordingly. Unlike the cheap waterproof laptop cases, the discount laptop cases comes in more reliable quality, have longer life and protects the device from every kind of damage. The discount waterproof laptop cases provides different compartments to carry extra stuff along the laptop such as CD’s, data cable, USB, Bluetooth and many more.

Mitch Edwards asked:


 

Laptops are fast becoming a necessity for professionals and students alike. Gone are typewriters, pen and papers and messy handwritings. One can easily take an office or a library anywhere he want with just a laptop.

High prices of brand new laptops however can be quite overwhelming for some people on a tight budget. So they can settle for cheaper kinds – used laptops or refurbished laptops. Used laptops are not highly recommend though, unlike refurbished laptops which are being raved on by many people today.

There are several advantages of buying Refurbished Laptop computers:

Reduced Cost: Buying refurbished laptop computers can save you 10 to 30 percent off the price of a new computer.

High Quality. Refurbished laptops go through high levels of performance standard tests at factories before they’re repackaged and sent out for selling. You are assured of a high quality laptop even though they’re refurbished.

Discounts. Usually, these refurbished laptops are offered at great discount prices for students, senior citizens, military personnel and etc. Aside from the 30 percent slash off, you can also get additional discounts!

Warranty Advantage. Oftentimes, these refurbished laptops come with longer warranty period. Normal warranties last for 1 year, while refurbished laptops can extended warranty period of up to 3 years.

Now you might be real excited to get that refurbished laptop for yourself. But wait, here are a few things to keep in mind before you buy a refurbished laptop:

First, you must check the date of the first purchase of the unit to know how old the hardware parts are – you don’t want to end up with a laptop filled with almost obsolete parts that’ll be difficult to repair or replace right? Second, you need to find out how many users the laptop had before. A laptop with 2 or more users probably will not be that good. The laptop’s condition is very important because you have to get the same kind of performance capability such as that of a new or a newer laptop. Many buyers also prefer laptops previously owned by women. Make sure that you buy a refurbished laptop from your own country so can easily reach the dealer without much hassle. Shop around till you find a good price for great quality. And lastly, make sure you buy a refurbished laptop that comes with a warranty. If the manufacturer’s warranty has already expired, the vendor then should give one. This way, you can reach the vendor if any problems, repairs or replacement arises.

Refurbished Laptops: Save on Cost, Not on Quality

Sometimes desktops and laptop computers seem to be priced real low. Descriptions of these products might include the term refurbished. Manufacturers and retailers offer refurbished systems much cheaper than normal PC and laptop costs, but are they safe to buy?

Refurbished laptops typically fall into two categories. First are the units which failed a quality control check during manufacturing. Rather than simply disposing them, manufacturers rebuild them to pass quality control checks but them sells them at discounted prices. Another kind is a rebuilt system from customer return maybe because of a certain component failure.

Refurbishment can be done by a manufacturer of a third party. While manufacturers rebuild the system with the same parts used in new laptops, third parties may use alternative parts to fix it up and get it running. These alternate parts may change the system from the original design so it is important for customers to read the specifications and compare them to the standard specs of the product.

And another type that customer will find discounted is an open box product, unlike refurbished laptops, these has not been rebuilt. The product is simply a customer return that was never opened and tested. Buyers should be very careful when purchasing any open box products.

Costs Savings

Primarily, cost savings is the one reason considered why many people purchase refurbished laptops. These are usually priced below average computer systems currently sold. But of course the reduced price is only relevant if you are looking at the same exact product. Most refurbished laptops available will typically be a bit older products that are being compared to the original suggested retail prices for the products on its first release. When looked at this way, deals may not always be the best.

When fishing for refurbished laptops, it is important to note if the model is still available for new sale. If it is, you can easily determine the price comparison. These usually have modest discounts of 10 to 25 percent off the retail prices. So long as they have similar warranties as the new ones, these can be an excellent way of having a laptop for a cheaper price.

However, customers are often tricked into paying for a unit that looks like a good deal but are actually not. This problem comes from older laptops that are no longer sold. This is where the specifications become tremendously important. Check out your prospective refurbished laptop’s specifications and try to find a comparable brand new or newer system. If you can find one, them the cost analysis of 10 to 25 percent still holds. But if you can no longer find a comparable system, search for a comparably priced system and see what you can get. In this case, customers usually will find that they can have a better, newer product for that same price.

So try to be careful when choosing refurbished laptops. Go for those refurbished by manufacturers to get real cost savings and better quality for your money.

Warranties

The key to any refurbished computer system is the warranty. These are products that typically were returned or rejected due to a defect. While that defect may have been corrected and no further problems may develop you want to make sure that some coverage is included for potential faults. The problem is that warranties are typically modified for refurbished products.

First and foremost, the warranty should be a manufacturer one. If the warranty is not provided by the manufacturer it should raise a red flag for consumers. A manufacturer warranty will guarantee that the system will be repaired to the original specifications with manufacturer parts or certified replacements can be used with the system. Third party warranties can cause major problems as replacements parts may not be guaranteed and it may take longer for the system to be repaired.

The next thing to look at is the length of the warranty. It should provide the same length as if it was purchased new. If the manufacturer is not offering the same coverage consumers should once again beware. The lower cost of the system may be the result of them not offering to support the product.

Finally, be wary of extended warranties. If an optional warranty is offered for purchase with the system, it should be a manufacturer extended warranty and not one through a third party. Also be wary of the cost for extended warranties. If the cost of the extended warranties makes the system cost more than buying it new, avoid the purchase.

Conclusions

Refurbished laptops and desktops are one way consumers can find a good deal, but they have to be much more informed before the purchase. The key is to ask several key questions to know if it is really a good and safe deal:

Is it sold by the manufacturer or a retailer? What is the price relative to the same PC new? Is the system comparable to an equivalent priced new PC? What type of warranty comes with the PC? Who will handle warranty work?

If all of these can be answered satisfactorily, then consumers can generally feel secure in the purchase of a refurbished PC.

What are refurbished notebooks

Imagine you could buy cheap, used laptop that fits all your performance and portability needs and keeps all advantages of new notebook like good condition, warranty and technical support. That’s what refurbished laptop is.

Before being offered as reconditioned each laptop is tested, than repaired (if anything needs to be repaired), than thoroughly tested again. Each notebook is also cleaned and comes with warranty. Sometimes warranty includes battery and sometimes not, depending on seller and offered laptop.

What vast majority of people really use laptop for are simple tasks like browsing the Internet, reading and writing e-mails, word processing or working with other office applications. These do not demand cutting-edge, flashing laptop packaged with the latest technical innovations and gadgets for over $2000. Even people doing more complex tasks like programming, web development or working with CAD/CAM applications do not need it in most cases. I run my CAD software on cheap, factory refurbished Dell Inspiron 1100 laptop for under $800. Before it also used to work fine on 900MHz IBM.

Factory remanufactured laptops

There are generally two ways to buy renewed laptop. The best is to buy factory remanufactured laptop directly from its manufacturer. Almost every bigger laptop manufacturer has an outlet section in its online shop, where you can find deals on refurbished notebooks. They are reconditioned and tested by qualified manufacturer’s technicians to meet the same requirements as new items. They also often come with the same warranty conditions and technical support as for new notebooks. The only significant difference is that they are from about $100 to several hundreds dollars cheaper than the same models new. Dell, IBM and Compaq  brands currently presented on our site, all run outlet shops on their web sites.

Third party reconditioned laptops

The second way is to hunt a deal from one of countless third party laptops resellers. Buying from third party reseller, you usually get better prices for the same items. You can also find older models that are not available on manufacturers sites. Each laptop is tested, repaired if needed and cleaned to be in good, working condition. They usually come with warranty but its period rarely extends 90 days. It is also common that battery is not covered by warranty. You can find very good deals on third party refurbished laptops but be careful to buy only from respected and established resellers.

I hope this site will convince you that good laptop doesn’t need to be expensive. The articles should answer most of your questions regarding laptop parts, equipment, accessories, peripherals and upgrading issues. Sellers review should help you to learn how to find quality online resellers. It also presents detailed description of several popular online resellers, where you can find deals on reconditioned and used computers. The brand categories you see at the top of the menu contain information on refurbished laptops offers from specific brands and reviews of the most popular and common models.

 

For more information on where to buy used laptops please visit buy used laptops now.

 

 

sam budhianto asked:


Broadband phone is the amazing technology to day that give many benefits for their users. Broadband phone actually uses voice over internet protocol (VoIP) to carry phone calls through the internet. This is an alternative way to transmit the call to the traditional telephony network.

How Does it Work?

Exactly, VOIP allows you to make phone calls through your internet connection, it works by converting a phone signal into ‘packets’ of information that are sent down an internet connection, and then converted back into an ordinary phone signal at the other end. A hardware broadband telephone uses an adapter. You connect this hardware to the router on your network or to your PC directly. Another option is software. The broadband software is a program that makes broadband calls.

For all VOIP, a broadband connection is essential. Most phones will take up around 64k for sending your voice, and 64k for receiving the other voice, so a 128k broadband is the absolute minimum requirement to ensure no gaps in call quality.

Advantages of Voip Broadband Phone Services :

1. Save money

Using VoIP Broadphone phone is a cheaper option if you make a lot of long distance and international calls. All calls between people using the same service provider are free regardless of location. Branch offices to head office communication be free cost, if we use this service. By using a VOIP system, you can save large amounts of money, its better choice than traditional phone.

2. Voip Features

Many features that support telecommunication user:

- call waiting

- caller ID

- three-way calling

- call forwarding

- last number redial

- speed dial

- voicemail

3. User Mobility

When traveling, you can take the VoIP adapter with you and instantly turn a phone anywhere in the world into your local phone. This will require a high speed internet connection. It’s flexible tool so your communication can moveable

4.Easier Call Directing

A major advantage of VOIP phones is that they allow a call to be directed to a phone, not a location. If for example, you travel between two broadband equipped offices (or even abroad), you could take the phone with you, and have all your calls go direct to you in either office, whilst an internal call from your VOIP system would still be free! This offers many of the benefits of mobile phones, but for far less cost.

How to choose a Broadband Phone ?

Essentially, there are two kinds of VoIP (Broadband Phone) applications to consider, either hardware or software based. If you choose the software solution, you’ll have to have your computer urned on in order to both make and receive telephone calls, but the only equipment you’ll need is a microphone and speakers connected to your computer.

If you choose the hardware solution instead, you’ll be using a converter box called an ATA that will be attached to your high-speed internet connection. Your telephone can then be plugged into the ATA. The converter box takes the analog signal from your phone and converts it to a digital signal to be sent over the internet in data packets, which are then reassembled on the other end of the telephone connection. By using a hardware VoIP (Broadband Phone) solution, you computer does not have to be on in order for you to make and receive telephone calls, although your Internet connection will have to be active. Many VoIP (Broadband Phone) service providers are including the ATA at very low cost or even for free in some cases.

Are there any disadvantages with a VoIP (Broadband Phone) solution?

Although most VoIP (Broadband Phone) service providers have Emergency 911 there are still a few that do not. To be sure, the biggest disadvantage that skeptics will throw at you is what happens when your power goes out at home or you lose your Broadband Internet connection. You see VoIP (Broadband Phone) relies on having a broadband connection so if that goes down so does your Internet phone service. However, in the days when most of us have a cell phone of some sort, even if it is just “pay as you go”, is this really a big issue? Another option that many people go for is to have a cheap regular local phone service to use just on those rare occasions when you lose your power or broadband connection.

Finally the best choice for your telecommunication that we suggest is voip broadband phone.

John Blake asked:


The massive growth and innovations in the mobile industry has brought diverse noteworthy changes in our lives. As far as capabilities of mobile phones are concerned, these devices are getting more powerful and accurate with high-tech features and technologies that you have never imagine before. These days, the old-designed of mobile phones that come in the shaped of brick have been revolutionized by the PDA type of mobile phones. The new mobile phone deals that are coming with the latest handsets will also give you the best experience of mobile telephony.

With the advent of new mobile phone deals, users have the great opportunity to select their desirable handsets in affordable prices. And these also make a big difference in their lives and thus the mobile market is flooded with countless high-end mobile phones. And most significantly, due to the growing demands of the dissimilar mobile phone users, all the leading handsets brands and network providers are also introducing new mobile phone deals to offer all the options of those smart users.

No doubt, there are also numerous well-liked mobile phone deals available in the fast-growing mobile market that offers attractive high-end mobile phones with free gifts. Some of the highly accepted mobile phone deals include pay as you go mobile, pay monthly mobile deals, contract mobile phones and 12 months free line rental.

Amongst them, pay as you go mobile offers its users to use their mobile phone according to their budget and they can control their mobile habits. With this new mobile phone deals, you have the flexibility and options to make the most of your mobile experience as you want. Due to its remarkable benefits, nowadays pay as you go mobile phone deals have been highly practice amongst teenagers, housewives and low income group of people. On contrary, contract mobile phones come with freebies and the users will get the high-end handsets for free.

Gill Critchley asked:


Technology giants Apple have recently filed a patent for a sat nav system that will focus on driver safety. The company stated details of the device in an 11 page document. The satellite navigation device could come as standard in a vehicle or could even be used via a docking station. In the document Apple states that there have been many incidents on the roads where sat navs have proved to be a danger to drivers, for instance, when the driver is focusing on the device rather than the roads accidents can be more common. As a result of this, they have stated in the 11 page document that their sat nav device would focus on driver safety. In an attempt to help remedy this, Apple has come up with a touch screen sat nav which will include a loudspeaker and hands-free voice commands which will enable the driver to concentrate more on the roads rather than the sat nav. An interesting study that took place at the beginning of this year showed that regularly using sat navs could mean an increased risk of suffering from car sickness. In-car navigation systems of the future are said to promote green driving by telling the driver when to change gear to maximise fuel economy and chastising the motorist if they are driving erratically. In an effort to make cars safer the car company Mazda has developed an early warning system, which applies the brakes early if it decides a crash is unavoidable. The car also has the ability to assess road conditions itself as well. If you’re interested in buying a sat nav, the best thing to do is to shop online so that you can compare the features and the prices and make sure you get the model that is exactly what you’re looking for.

Apple’s satellite navigation system will focus on driver safety and will include features that make the device a safer one to use on the roads. A recent study showed that sat navs could mean an increased risk of suffering from car sickness. To find the best deals on sat navs it’s best to shop online

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Astin Sharon asked:


The charm and curiosity for mobile phones among the consumers have forced the mobile phone companies to multifold their production. Many innovations have been witnessed in diverse fields including the telecommunication sector. Mobile companies bring handsets keeping in mind the buying mindset of the consumers to encourage their sales. Today’s era is full of electronic gadgets which are considered to be most user friendly entertainment products. And mobile phone constitutes a vital part of it.

How to Buy Cheap Mobile Phone?

If you think that buying mobile phone is not a difficult task as one can go to the dealer or priority shop and select any favorite handset then you are wrong because most of the people are not aware that they can buy cheap mobile phones from different sources other than conventional retail stores and dealers. It has been found that such conventional methods try to maximize their own profit by offering you mobile phones at quite higher price. Further with the availability of several mobile phone companies offering wide range of handsets, people often get in to a situation where they find themselves unable to reach to definite decision to buy any handset. Also the misleading ads on television make their condition worse as each of the handset promises to be superior to their opponents.

The ultimate solution for such a problem is accessing all information about handsets and best mobile phone deals online. Some of the websites provide you comprehensive information about all leading mobile phone companies and network service providers offering best mobile phone deals. cheap-mobile-deals is one of the leading website providing a host of mobile phone information with specifications and features of each of the handset. Further it acts as a hub for accessing product offering from all leading mobile phone manufactures and network service providers. Some of the service providers include T mobile phone, 3 mobile phone and many more.

Now you may be wondering that how one can buy cheap mobile phones from online resources. Well many service providers and handset makers offer best mobile phone deals to lure the consumers and increase their sales. Deals like contract mobile phone and payg mobile phone mainly act as the perfect method to buy cheap mobile phones. Contract mobile phone deal allows user to use the handset of his choice by giving monthly price to the service provider and payg deal enables user to cut down mobile phone expenses as he pays the amount in advance for the talk time he needs.

All the new mobile phones recently arrived in the market are also offered by online resources. So guys don’t end up in spending more money while shopping for mobile phones, just access Internet to make your purchase worth!

Jason Hellyer - Mobile Guide asked:


I often joke with my new client’s that we (mobile phone companies) purposely make mobile phone bills confusing just to make it difficult for them to see exactly what they’re being charged.

If you’re often having difficulty making sense of the fees and charges that appear on your mobile phone bill then perhaps the information I’ve appended below will help you get a better understanding of how to accurately read and decipher your account.

HOW TO DETERMINE YOUR MOBILE PHONE CALL RATES

Probably 80% of the clients I meet don’t have a clear understanding of their mobile phone call rates; or what they believe they’re are being charged and what is actually being charged are two completely different things! To calculate your mobile phone call rates follow these steps:

a). FIND A 30 SECOND PHONE CALL

b). FIND A 1 MINUTE PHONE CALL

c). DEDUCT THE COST OF THE 30 SECOND CALL (a) FROM THE 1 MINUTE CALL (b)

This will generally provide you with your “real” call cost per 30 seconds. You’ll now notice that the new 30 second charge varies from the 30 second phone call cost (a) that you found in your mobile phone bill. This variance is due to an additional fee referred to as “flagfall” or “connection fee”. If you now deduct the new 30 second phone call cost from the original 30 second phone call cost (a) you’ll end up with a figure that is your flagfall cost per phone call.

WHAT IS FLAGFALL?

Flagfall (or connection fee) is what I call the “hidden fee” that many client’s either forget they’re being charged, or in some cases, were never told they’re being charged. Flagfall is a “single” fee applied at the beginning of a phone call every time you “connect” to someone (or something) on the other end. Simply put - if you make a phone call and someone (or something) answers, you’re charged flagfall. If nobody answers and the call “rings out” no flagfall fee applies. Many clients ask “what if I get someone’s message centre, am I still charged flagfall?” and the answer is “yes”. In this scenario your mobile phone call has still connected with something on the other end and therefore flagfall and call costs apply.

CHECK YOUR WHOLE BILL

Call rates and flagfall fees vary from carrier to carrier, plan to plan and call to call (see we really do try to make things confusing!) and this greatly depends on the type of plan or plans you and your business is subscribed to.

To give you a rough guide, in my experience CAP PLANS tend to have higher flagfall fees than BUSINESS PLANS and on occasions some BUSINESS PLANS may have no flagfall fee at all. You may even find that flagfall (and call costs) vary depending on the type of call that you make. For example, a call to a “landline” (office number) may be charged at a higher rate than a call made to a mobile phone, or a call in the morning may cost less than a call made in the afternoon!

So as you can see there are many variables that need to be considered when trying to accurately establish what you and your business is being charged for mobile phone calls.

I trust these simple “Tips & Hints” will help you make sense of your next mobile phone account.

Jason Hellyer

Mobile Guide

Karl Bantleman asked:


Satellite navigation systems for your car used to be expensive accessories. But due to the rapid development of technology and rising competition, prices have slumped over the past few years so that almost everyone can afford sat navs nowadays.

The technology of satellite navigation systems resembles the one once used in submarines when they were on or near the surface and is the main global positioning system (GPS) of international military services. While originally developed and designed for military purpose in 1960-70 sat navs are now available for civilians, too. The principle is based on satellite signals determining the position of a sat nav receiver which is part of every in car sat nav system. Military devices have an astonishing accuracy with a maximum error of only one metre. Even though civil sat navs can’t keep up to this, they can easily position where about on a road the receiver is. However, the accuracy mainly depends on the number of satellites supporting a signal.

As a consequence of the rising popularity of sat nav systems for cars, the latest devices don’t only locate your position and give directions but include traffic, conjunctions warnings and even roadwork. Here, the recently launched TomTom Go 720 Traffic Edition has set a new milestone. It is able to receive live traffic updates via an RDS signal and takes them into consideration when calculating routing. It further suggests alternative directions if necessary and provides different routes depending on the day and time.

Nevertheless, with these additional features TomTom introduced a new generation of sat navs and thanks to an improved sensitivity to satellite signals almost no accuracy errors occur. It is expected that other leading manufacturers like Navman and Garmin will soon offer similar products with an equivalent feature. With a price range of over £200 the TomTom Go 720 Traffic Edition is still reasonably priced considering the technology. However, it might be worth being patient and waiting for a second generation as usually technical innovation comes along with troubles and often needs to be improved and adjusted.

Generally speaking, a sat nav is useful for every driver and especially for those who think that the philosophy of getting from A to B is more a game of pure chance than logical routing. If you tend to write directions down rapidly on a piece of paper, napkin or anything else that’s just within your reach then you should go for a reasonably priced satellite navigation system. This will not only save you money but also valuable time and you’ll reach your destination more relaxed.

Where would we be without our GPS systems? Many of us now have some kind of satellite navigation and as it eliminates stress and hassle, many more will look to Sat Nav to find their way.

 

harinath asked:


MOBILE COMMUNICATIONS

Mobile communication is the application of wireless technology in the access network. It offers many useful features,

• Easy installation for rapid roll out

• Proven platform with scalability

• Future proof

• Reliable and secure

• Mobility

It is a very rapidly growing and popular service which was revolutionised telecommunications. It has become a backbone for business success and efficiency. It connects subscribers to the public switched telephone network(PSTN) using radio signals as a substitute for copper.it allows any body to communicate with any one while on the move.

Different technologies emerged for different types of requirements-coverage, capacity, mobility, bandwidth.

GSM

CDMA

CORDECT

PHS

AMPS,DAMPS

EVOLUTIONS OF MOBILE COMMUNICATIONS:-

FIRST GENERATION(1G):ANALOG CELLULAR:-

The introduction to cellular systems in the late 1970s and early 1980s represented a quantum leap in mobile communication(especially in capacity and mobility). Semiconductor technology and microprocessors made smaller and lighter weight , and more sophisticated mobile systems a practical reality for many more users. These 1G cellular systems still transmit only analog voice information. The most prominent 1G systems are ANALOG MOBILE PHONE SYSTEM(AMPS), NORDIC MOBILE TELEPHONE(NMT) and TOTAL ACCESS COMMUNICATION SYSTEMS(TACS). With the 1G mobile introduction, the mobile market showed annual growth rates of 30 to 50 percent, rising to nearly 20 million subscribers by 1990.

SECOND GENERATION(2G):MOBILE DIGITAL SYSTEMS:-

The development of 2G cellular systems was driven by the need to improve transmission quality, system capacity and coverage. Further advances in semiconductor technology and microwave devices brought digital transmission to mobile communications.sppech transmission still dominates the airways,but the demands for fax,short message and data transmissions are growing rapidly. Supplementary services such as fraud prevention and encrypting of user data have become standard features that are compatible to those in fixed networks. 2G cellular systems include GSM, DIGITAL AMPS(D-AMPS),CDMA and PERSONAL DIGITAL COMMUNICATION. Today multiple 1G and 2G standards are used in world wide mobile communications. Different standards serve different applications with different levels of mobility, capability and service area standards are used only in one country or region and most are in compatible.

2G TO 3G GSM: EVOLUTION:-

Phase 1 of the standardization of GSM 900mhz band was completed by the EUROPEAN TELECOMMUNICATION STANDARD INSTITUTE (ETSI) in 1990 and included all necessary definitions for the GSM network operations. Several tele services and bearer services have been defined (including data transmission upto 9.6kbps), but only some very basic supplementary services offered. As a result, GSM standards were enhanced in phase 2 (1995) to incorporate a large variety of supplementary services that were compatible to digital fixed network integrated services digital network(ISDN) standards. In 1996, ETSI decided to further enhance gsm in annual phase 2 + releases that incorporate 3G capabilities.

LIMITATIONS IN 1G AND 2G SYSTEMS:-

• No global standards

• No common frequency band

• Low information bit rates

• Low voice quality

• No support of video

• Various categories of systems to meet specific requirements

figure shows the architecture of GSM.

INTERNATIONAL MOBILE TELECOMMUNICATIONS 2000:-

IMT:-A future standard in which a single inexpensive mobile terminal can truly provide communications any time and any where. The main characteristics of 3G systems, known collectively as IMT-2000 are a single family of compatible standards that have following characteristics

• Used world wide

• Used for all mobile applications

• Support both packet witched(PS) and circuit switched(CS) data transmission

• Offer high data transfer rates 2MBPS.

• Offer high spectrum efficiency

IMT standards has made 17 proposals to meet the requirements of 2G systems.The most important IMT-2000 proposals are the UMTS (W-CDMA) as the successor to GSM,CDMA as the interim standard 95(IS 95) successor and time division synchronous(TD-SCDMA), UNIVERSAL WIRELESS COMMUNICATIONS-136(UWC 136/EDGE) as TDMA based enhancements to DAMPS/GSM all of which are leading previous standards toward the

ultimate goal of IMT 2000. The goals of the services to be provided in 3G systems by IMT 200 is shown in figure The Global System for Mobile Communications (GSM) is now the world’s most successful wireless standard. Recent figures indicate that GSM has more than 100 million subscribers in 120 countries and attracts more than five million new users every month. There are nearly 300 GSM system operators worldwide. Current wireless or mobile systems, despite their evolution, are still constrained in terms of the data rate they can offer and their flexibility to manipulate complex, yet user-friendly multimedia services. This need presents the opportunity to the mobile radio, IT, and consumer electronics communities to offer users a mobile system capable of managing and delivering a much wider range of information services to the mass market. Elements of this opportunity include:

• An industry-wide and government commitment across the world;

• A coordinated program including spectrum, standards, and technology; and

• Synergy of communications, IT, and media workings to bring about global opportunities for businesses and consumers, while creating new ways of doing business, entertaining and informing.

A new mobile system for worldwide use is now being developed to enhance and supersede current systems. The Universal Mobile Telecommunications System (UMTS) will be an enhanced digital communications system that will provide universal communications to anyone, regardless of their whereabouts. UMTS will allow for wireless Internet access, video-conferencing, and other bandwidth intensive applications. Benefits from this new system of wireless communications are expected to be:

• Support to existing mobile services and fixed telecommunications services up to 2Mb/s;

• Support to unique mobile services such as navigation, vehicle location, and road traffic information services, which will become increasingly important in world market;

• The ability to enable the use of the system terminal from multiple environments - in the home, the office, and in the public environments -in both rural areas and city centers; and

• Provision of a range of mobile terminals - from a low cost pocket telephone to sophisticated terminals to provide advanced video and data services .

UNIVERSAL MOBILE TELECOMMUNICATION SYSTEMS(UMTS):-

INTRODUCTION:-

In January1998, the European Telecommunications Standards Institute (ETSI) decided on a single air interface standard for the proposed Universal Mobile Telecommunications System (UMTS). The system is one of the major new third-generation mobile systems being developed within the framework that has been defined by the International Telecommunications Union (ITU) and is known as IMT-2000. UMTS has been the subject of intense worldwide efforts on research and development throughout the past decade. The system has the support of many major telecommunications operators and manufacturers because it represents a unique opportunity to create a mass market for highly personalized and user-friendly mobile access to today’s information society. The system seeks to build on and extend the capability of today’s mobile, cordless, and satellite technologies by providing increased capacity and data capability as well as a far greater range of services using an innovative radio access scheme and an enhanced, evolving core network.The system will be a member of a new family of mobile telecommunications systems being developed by the ITU for deployment across the world. While using different radio frequencies in different countries, every system will offer the same set of features to users. This will allow handsets to be developed that can be carried from country to country as the user travels.

The key difference between this system and previous mobile (wireless) systems, such as GSM, is that the earlier systems were conceptually separate from the fixed (wire line) telephone network. The goal of this system is to integrate wire line and wireless systems to provide a universal communications service, such that a user can move from place to place while maintaining access to the sum set of services .

The system is intended to allow users to send and receive data at much higher bandwidths than supported by today’s GSM system. While on the move, users will be able to access remote systems at up to 144Kbps. When stationary, connections of up to 2Mbp/s will be supported through wireless access to networks, with much higher performance being possible by plugging the handset into a network socket .

ETSI has chosen aggressive timescales for the introduction of UMTS in order to meet the demands of customers. The target date for its introduction has been set as the year 2002. figure shows the architecture of UMTS.

To meet the deadline, the ETSI is following a phased approach in hopes of allowing capabilities to improve over time following the initial system introduction. At launch, terrestrial UMTS will have the capability for data rates up to 2Mb/s. However, UMTS is designed as an open system that should allow for evolution to incorporate new technologies as they become standardized.

UMTS CRITICAL TECHNOLOGIES:- Some of the critical technologies essential for the successful introduction of UMTS are described below:

1)UMTS Terrestrial Radio Access (UTRA):-

The ETSI decision in January 1998 on the radio access technique for UMTS combined two technologies. The W-CDMA for paired-spectrum bands and TD-CDMA for unpaired band². The idea was to develop a common standard to ensure an optimum solution for all the different operating environments and service needs .

The transmission rate capability of UTRA will provide at least 144 Kbit/s for full mobility applications in all environments, 384 Kb/s for limited mobility applications in the macro- and micro-cellular environments, and 2.048 Mb/s for low mobility applications particularly in micro-cellular environments. The 2.048 Mb/s rate may also be available for short range or packet applications in the macro-cellular environment, depending on deployment strategies, radio network planning, and spectrum availability.

2)Multi-mode Second Generation/UMTS Terminals:-

UMTS terminals will exist in a world of multiple standards that will enable operators to offer maximum capacity and coverage to their user base by combining UTRA with second- or third-generation standards. Therefore, operators will need terminals that are able to interwork with legacy infrastructures such as GSM/DCS2800 and DECT, as well as other second-generation, worldwide standards (such as those based on the US AMPS standard) because these may initially have more complete coverage than UMTS. Many UMTS terminals will therefore be multi-band and multi-mode. Building such terminals at a cost which is comparable to contemporary single-mode, second-generation terminals will become possible because of technological advances in semiconductor integration, radio architectures, and software radio.

3)Satellite Systems:-

At initial service launch in 2002, the satellite component of UMTS will be able to provide a global coverage capability. Implementation plans call for utilization of the S-band Mobile Satellite Service (MSS) frequency allocations identified for satellite IMT2000 and will provide services compatible with the terrestrial UMTS system .

4)SIM Cards/Smart cards:-

GSM introduced the Subscriber Identity Module (SIM) or Smart Card. SIM technology incorporates enhanced security and a degree of user customization to the mobile terminal. SIM requirements, security algorithms, card and silicon IC technology will continue to evolve up to and during the period of UMTS deployment . The smart card industry anticipates being able to offer cards with greater memory capacity, faster CPU performance, contactless operation, and greater capability for encryption. These advances will allow the UMTS Subscriber Identity Module (USIM) to add to the UMTS service package by providing portable high security data storage and transmission for users. In addition, the users will be able to store, down or upload images, signatures, personal files, fingerprint or other biometrics data through the card. Contactless cards will allow the users to perform business transactions such as electronic commerce or electronic ticketing without having to be removed from a wallet or phone .Electronic commerce and banking activities, utilizing smart cards, is expected to become widespread. Users will expect and be able to use their cards on any terminal over any network. New memory technologies can be expected to increase card memory sizes making larger programs and more data storage feasible. Several applications and service providers could be accommodated on one card. In theory, the users could decide which applications/services they want on their cards, much as they do for their desktop computers’ hard disks .

5)Internet Protocol (IP) Compatibility:-

UMTS is a modular concept that takes advantage of the trend towards convergence of fixed and mobile networks and services, enabling a host of new applications. For example, a laptop with an integrated UMTS communications module becomes a general-purpose communications and computing device for broadband Internet access, voice, video telephony, and conferencing for either mobile, office, or residential use.UMTS may well become the most flexible broadband access technology available, as it allows for mobile, office and residential use in a wide range of public and non-public networks. The system can support both IP and non-IP traffic in a variety of modes including packet circuit switched and virtual circuit². UMTS will be able to benefit from parallel work by the Internet Engineering Task Force (IETF) who is further extending its basic set of IP standards for mobile communication . New developments like IP version 6 allows parameters such as quality of service, bit rate, and bit error rate (BER), vital for mobile operation, to be set by the operator or service provider. Developments on new domain name structures are also taking place. These new structures will increase the usability and flexibility of the system, providing unique addressing for each user, independent of terminal application or location .

6)Cross platform interoperability:-

The need for the ability to transport multimedia content over various types of networks requires industry to develop cross-platform interoperability because the properties of the networks may have an effect on the content of the transmission. In many cases several different kind of networks will be cascaded (i.e. Ethernet, ATM, X.25 and UMTS) .

7)API and Development toolbox:-

It is expected that rapid development and deployment of new and innovative services will drive the UMTS market. A key enabler in this area will be the standardization of the UMTS application-programming interface (API). API allows for abstraction of both the terminal and the network. It will also provide a generic way for applications to access terminals and networks. The API will allow the same application to be used on a wide variety of terminals and will also provide a common method of interfacing applications to UMTS networks. The API will support security, billing, subscriber information, service management, call management, SIM management user interaction and content translation. It is expected that the API will build upon and extend today’s technologies (i.e. Java, Wireless Application Protocol (WAP), GSM SIM Toolkit and Internet technologies) that exploit convergence with other emerging technologies for consumer products (such as digital televisions).

8)Client server architecture:-

One of the primary drivers for UMTS is service differentiation. UMTS allows network operators to market products based on more than just coverage and

capacity issues. The key to this benefit is the ability to develop and offer new products and features in short timescales, without requiring modifications from infrastructure suppliers.

figure shows client server architecture of UMTS.

Many new developments in the IT industry are based on a client/server technology, which allows intelligence to be downloaded transparently from a server into the user’s terminal. The technology provides direct and immediate high performance user interaction and interpretation. On the other hand, tasks that must remain centralized, such as database residence, are held on central servers waiting to rapidly and efficiently respond to queries from the clients. However, in the mobile industry, intelligent terminals and USIM card will allow personalization of the user interface and provision of features not possible with basic terminals in today’s client/server networks. As roaming traffic continues to increase, the ability to provide such features independently of the serving network will become increasingly important. Existing and evolving GSM standards, such as SIM Toolkit and Mobile Execution Environment, together with other initiatives such as WAP, provide the framework for delivering this enhanced client/server approach. The user of an object-oriented language such as Java is attractive because it is platform and operating system independent, and optimizes the download .

9)Customer Care and Billing Systems:-

UMTS will operate in a very different environment than today’s mobile systems. Customer care and billing are inextricably linked. These systems must be able to effectively operate with all UMTS users and providers in a customer-friendly manner. For UMTS, a bill will no longer be just a dun but, instead, a key part of a highly sophisticated approach to customer care across all provider services. Convergence will not only require the interoperation of fixed, mobile, satellite, private and public systems but also the integration of players from non-telecommunications fields such as finance, entertainment, and the news media. This will require a harmonized solution to customer care and billing systems despite very different legacy practices.

The competitive services market will demand multiple flexible interconnections between players and roles. Seamless delivery will require a unification of management and a means to provide interworking without a prior relationship. Significantly higher levels of automation and timeliness will be required to support the billing and customer care operations. In addition, fraud management will need to be applied across the whole value chain. Charging and billing will need to mature as concepts and practices.

BENEFITS OF UMTS: what it offers?:-

Corporate use of UMTS (including global mobile access to Intranets) will be a key driver for UMTS. Businesses will demand greater flexibility for customization and more devolved service control to optimize productivity and operational efficiencies within corporate networks. UMTS subscriber and network management capabilities will offer enhanced capabilities to meet these new and evolving requirements .

The body of literature on UMTS indicates that it offers the promise of being a significant advancement in mobile communications technology. UMTS is being designed to ensure flexibility is presented to users, network operators and service developers. UMTS will offer significant benefits in communication abilities including:

• Ease of use and low cost;

• New and better services;

• Packet transmission and data rates on demand; and

• Improved mobility and coverage.

1)Ease of use and low costs:- Wireless customers want useful services, easy-to-use terminals and good value for money, UMTS is envisioned to offer services that are easy to use and customizable in order to address individual user needs and preferences. Terminals and other customized equipment will be available to allow easy access to these services. A wide array of inexpensive, available terminals and other periphery will be available. Costs for the actual UMTS service are projected to be low enough to ensure a mass market and provider competition.

2)New and better services:- Market studies show that voice will remain the dominant service for existing fixed and mobile telephone networks, including GSM, through 2005. Users will demand low-cost, high-quality voice service from UMTS. However, the opportunity for increased revenues through UMTS comes from offering advanced data and information services. Long term, industry forecasts for UMTS show a strongly growing multimedia subscriber base by the year 2010.

3)Fast access:- One factor, which clearly sets UMTS above the second-generation mobile systems, is its potential to support 2Mb/s data rates for users from the outset. This capability, together with inherent Internet Protocol (IP) support of UMTS, is a powerful combination to deliver interactive multimedia services as well as other new wideband applications such as video telephony and video conferencing.

As the demand for user data rates increases in the long term, UMTS will be developed to support even higher data rates, perhaps one or two orders of magnitude greater. In later phases of UMTS development, there will be a convergence with even higher data rate systems using mobile wireless Local Area Network (LAN) technologies (microwave or infrared) providing data rates of for example 155 Mb/s in indoor environments .

4)Packet transmission and data rate on demand.:-Most cellular systems in use today use circuit-switched technology for wireless data transmission. However, UMTS integrates packet and circuit data transmission. Packet data over the airwaves provides the user several benefits:

• Virtual connectivity to the network at all times;

• Alternative ways of billing. For example, pay-per-bit, per session or flat rate per month; and

• Asymmetric bandwidth in the uplink and downlink. As demanded by many emerging data services where one link direction carries simple commands and the other carries and content rich, bandwidth intensive traffic (for example Web browsing or video transmission).

UMTS is also being designed to offer data rate on demand, where the network reacts flexibly to a user’s demands based upon his or her profile and the current status of the network. The use of packet-oriented transport protocols such as Internet Protocol (IP) for UMTS is being studied now. The combination of packet data and data rate on demand will remove technical barriers for the user and make operation of the system much cheaper. Simply put, there should be no worries about how and when to connect to the network.

UMTS services are based on standardized service capabilities, which are common throughout all UMTS user and radio environments. This means that a user will experience a consistent set of services even when he or she roams from his or her home network to other UMTS operators. Users will find the same interface, whether they are in their home network or roaming. The Virtual Home Environment (VHE) will ensure the delivery of the service provider’s total environment, including for example, a corporate user’s virtual work environment, independent of the user’s location or mode of access (satellite or terrestrial).

VHE will also enable terminals to negotiate functionality with the visited network, possibly even downloading software so that it will provide “home- like” service. The ultimate goal is that all networks, signaling, connection, registration and any other technology should be transparent to the user so that mobile multimedia services are simple, user friendly and effective.

Mobility and Coverage:- UMTS has been designed from the outset to be a global system, comprising both national terrestrial and global satellite components. Through multi-mode, multi-band terminals it can use 2nd generation systems to extend its coverage for basic services. The overall goal of the system offering is to achieve truly personal communications using terminals that are able to roam from a private cordless or fixed network (Figure 1). A second goal is to achieve this with a consistent delivery of the services via VHE.

Figure 1. UMTS Coverage is Universal (Leino, 1999).

The UMTS radio access system UTRA will support operation with high spectral efficiency and service quality in all the physical environments in which wireless and mobile communication take place. Today’s users live in a multi-dimensional world, moving between indoor, outdoor urban and outdoor rural environments with a degree of mobility ranging from stationary through pedestrian up to very high vehicular speeds. There are also different user density environments, including three-dimensional situations in high-rise buildings. UTRA has been specified for all these environments.

Limitations of UMTS:-

In practical implementations of UMTS, some users may be unable to access the highest data rates at all times. For example, the physical constraints of radio propagation and the economics of operating a network will mean that the system services might only support lower data rates in remote or heavily congested areas. Therefore, in order to ensure that the subscriber is always able to use their terminal, services will be adaptive to different data rate availability and other Quality of Service parameters.

In the early stages of UMTS deployment, traffic will probably be generated predominantly in locations such as airports and railway stations which operators will cover immediately following network launch. However, users will want full coverage so that they can access their services wherever they are . To offer this, UMTS technology is being defined to enable roaming with other networks. For example a GSM system operated by the same operator or alternatively by roaming agreements with other networks such as other GSM based systems or other third generation systems including UMTS compatible satellite networks, which will effectively be able to offer global coverage.

The limitations are,

1)Risk of further regulation:- There is a certain anxiety that an attempt to achieve circulation by means of administrative measures may lead to heavier regulation of UMTS (e.g. in the form of complicated procedures or excessive marking). Therefore, current efforts are intended to take care to aim to simplify regulation in all circulation measures.

2)Standardization:- Standardization will remain a key factor in providing quality services at an affordable cost and enabling roaming between systems. The success of UMTS depends upon the flexibility of interfaces and the capacity to evolve in parallel with technological development. Continued close co-operation between operators, manufacturers and regulators in the standardization of UMTS/IMT 2000 is crucial for successful harmonization of standardization proposals.

UMTS in the Long Term:-

In order to ensure that UMTS flourishes in the long term, its capabilities must be progressively increased by the addition of new technologies. These technologies are discussed below.

1)Re-configurable Terminals:- UMTS terminals will have to exist in a world of multiple standards, both second-generation standards and other members of the IMT-2000 family. In order to provide universal coverage, seamless roaming and non standardized services will no longer have fixed parameters, rather they will be in the form of a “toolbox” whereby the key parameters can be selected or negotiated to match the requirements of the local radio channel.

In addition to the capability to adapt to different standards as described above, terminals will enable network operators to distribute new communications software via download over the air in order to improve the terminals’ performance in the network or to fix minor problems (e.g. an improved handover algorithm). This aspect of software downloads will generally be invisible to the user.

2)Application and Service Download:- When using today’s multimedia terminals (e.g. PCs), users have accepted the idea that the capabilities of the terminal can be modified over time through a software download. It is now commonplace for a user to download a new “plug in” (for example a video or audio code) to access new types of content. The introduction of multimedia services on UMTS will take this concept into the mobile domain. UMTS “plug ins” will come from a variety of sources, for example:

• Pre-installed on the users’ terminal by the network operator or service provider;

• Downloaded over the air, at the user’s request or automatically by the network - much as today, where many Internet service providers upgrade one’s software or databases during a session; and

• Supplied on media such as DVD or CD-ROM.

Smart Antennas:- Smart antennas react intelligently to the received radio signal, continually modifying their parameters to optimize the transmitted and received signal. This allows them to:

• Increase coverage and capacity by reducing interference between adjacent mobiles;

• Offer space division multiple access, where frequencies are assigned on a per-mobile rather than a per-cell basis allowing vastly increased capacity; and

• Enable user location in space, allowing the introduction of advanced location based services.

Broadband Satellite Systems:- Several broadband satellite systems are also planned for deployment in the post-2002 timeframe to offer data rates beyond 2Mb/s and into the Gigabits domain. Some of these systems may offer compatibility with UMTS service concepts using satellite frequency allocations in the 20-30 GHz range. The requirements of the terminal equipment and higher power consumption will necessitate larger size transportable or fixed terminals or smaller electronic components.

CONCLUSIONS:-

UMTS appears to offer significant benefits to personal and commercial endeavors. Technologies are being put in place to bring it into the mobile community. A phased introduction of UMTS hardware and services with coverage, capability and number of operators growing over time. This phased introduction ensures early availability of services to users while reducing risks for UMTS operators and manufacturers.

UMTS must be capable of co-existing and working with existing second-generation mobile communications technologies so that operators can choose to reuse their existing infrastructure assets and expertise. Global availability of UMTS servers will be ensured by providing for roaming between members of the IMT-2000 family and handover between GSM and UMTS. A number of technologies are required, in addition to the radio interface on which so much focus has been placed recently. Although most current attention is focused on the early years of deployment, UMTS is being defined with a view to the long term.

UMTS is a significant opportunity for manufacturers, operators, and content providers as a communications system and as a part of the greater information society. The vision of UMTS is as a customer-focused system, where customers include both network operators and end users. The challenge to the communications industry is to integrate the technologies needed for UMTS in a way which supports this goal and thereby transforms the vision for UMTS into reality.