Tags |
|
|
Member You - Mobile Telephony
If your like many another webmasters you might be thinking of starting a web hosting company. But where do you start? And more importantly, what do you need to know? Well, in this article I will show the basic things that you will need in order to succeed as a web hosting provider.Before you start make sure this is something that you have the knowledge to do and not just from reading books, but where you have worked on them. Running servers may sound easy, but it's far from easy, in fact, even people experienced with servers will have trouble with them from time to time. You will have to deal with security threats, downtime and fixing program errors.Starting your own hosting services is going to be challenging and frustrating. One option to think about is reseller hosting plans. There are several good w
Table 7–1 Allocated Frequency Bands in the U.S.
System Mobile to Basestation Basestation to Mobile
Cellular 824–849 MHz 869–894 MHz
PCS 1850–1910 MHz 1930–1990 MHz
SMR 806–824 MHz 851–869 MHz
Another way these services differentiate themselves is by the technology used to transport the voice signal. The earliest mobile phone systems used analog voice signals, while the newer ones use digital. (In the not-too-distant future, I predict there will be no more analog systems.) In the case of the first cellular systems, the upgrade to digital technology used much of the existing infrastructure, including the assigned frequency bands. These new digital systems differentiate themselves by the modulation they use to encode the digital inf
In the not-so-recent-past, job seekers had to spend hours upon hours walking around visiting companies and career consultants hoping to get a good job. They had to pour over newspapers and job listings for hours and then call up every prospective employer to ask for an appointment. But the advent of the Internet has changed all that. Now one of the most effective and efficient ways to look for a job is by using online career services. Unlike days past, the new online job services offer comprehensive advice concerning interviews, resume writing, and even career coaching – all at reasonable prices, and some services are free of charge.Online Career Sites- Job Searching Made SimpleOnline career sites started out small – but with time they have become bigger and better, and offer more value-added se
In any event, it is good to understand the underlying technology of this lifestyle-altering wireless service. This article gives you a top-down view of mobile telephony, which includes a discussion of basestations, mobile switching centers, and what makes it mobile. But you will not be spared the details. You will also learn about frequency reuse, air interfaces, and the specific inner workings of an actual cellular phone.
CDMA, which is a popular air interface (and getting more popular all the time), is a mystery to most people. You may know what CDMA stands for, but it is doubtful that you understand how it works. Well all that is about to change. In recognition of its growing importance in the world of mobile telephony, an entire section of this article is devoted to explaining how CDMA (and spread spectrum) can cram more phone calls into a given bandwidth than any other air interface. Finally, this article concludes with an abbreviated discussion of the migration paths to 3G (third generation cellular service). As much as I would like to tell you that this article will clear up the mess that is 3G, I'm just not that good. The reality is that the paths to 3G nirvana (circa 2001) are a free-for-all. Different technologies using different frequencies (some not yet allocated) in different parts of the world are all trying to accomplish the same thing: make a lot of money for the service providers. Because of all these incompatible approaches, the one truly noble goal of 3G—international uniformity—is not likely to happen any time soon. What will be the outcome? If I knew that, I'd have to charge a lot more for the book. Stay tuned.
A World of Choices
Differentiators There are many choices for mobile telephone service in the United States. Each of these systems has one or more distinguishing characteristics that differentiate it from the others. One of the most prominent ways that these mobile telephone services differentiate themselves is by frequency. Each service is allocated a different frequency band in which to operate. The first mobile service offered in the U.S., and the one that is most commonly referred to as "cellular," operates in the 900 MHz band. The newer mobile service in the U.S., dubbed Personal Communications Service (or PCS), operates in the 1900 MHz band. In some cases, the only thing that separates "cellular" from PCS is the frequency band of operation. All other aspects of the technology are identical. (Of course the marketing people at the PCS companies don't want you to know that.) Table 7–1 is a summary of the frequency band allocations for some mobile services in the United States.
Table 7–1 Allocated Frequency Bands in the U.S.
System Mobile to Basestation Basestation to Mobile
Cellular 824–849 MHz 869–894 MHz
PCS 1850–1910 MHz 1930–1990 MHz
SMR 806–824 MHz 851–869 MHz
Another way these services differentiate themselves is by the technology used to transport the voice signal. The earliest mobile phone systems used analog voice signals, while the newer ones use digital. (In the not-too-distant future, I predict there will be no more analog systems.) In the case of the first cellular systems, the upgrade to digital technology used much of the existing infrastructure, including the assigned frequency bands. These new digital systems differentiate themselves by the modulation they use to encode the digital inf
In the securities market of the Czech Republic corporate governance plays a crucial role in instilling investor confidence and ensuring an efficient market. Post the fall of Communism, the economy was transitioned from state owned to capitalist in a very short time. Since then, the Czech Republic has come a long way to quickly reach standards of other capitalist markets and successfully obtain accession into the European Union. As the market continues its progression, the need for transparency of information and alignment between board members and managers in firms greatens.From the Czech Republic’s voucher privatization program in 1992 to the late 1990’s, corporate governance was viewed negatively and/or non-existent for publicly traded Czech companies. A path began with a lack of regulation, continued with a
CDMA, which is a popular air interface (and getting more popular all the time), is a mystery to most people. You may know what CDMA stands for, but it is doubtful that you understand how it works. Well all that is about to change. In recognition of its growing importance in the world of mobile telephony, an entire section of this article is devoted to explaining how CDMA (and spread spectrum) can cram more phone calls into a given bandwidth than any other air interface. Finally, this article concludes with an abbreviated discussion of the migration paths to 3G (third generation cellular service). As much as I would like to tell you that this article will clear up the mess that is 3G, I'm just not that good. The reality is that the paths to 3G nirvana (circa 2001) are a free-for-all. Different technologies using different frequencies (some not yet allocated) in different parts of the world are all trying to accomplish the same thing: make a lot of money for the service providers. Because of all these incompatible approaches, the one truly noble goal of 3G—international uniformity—is not likely to happen any time soon. What will be the outcome? If I knew that, I'd have to charge a lot more for the book. Stay tuned.
A World of Choices
Differentiators There are many choices for mobile telephone service in the United States. Each of these systems has one or more distinguishing characteristics that differentiate it from the others. One of the most prominent ways that these mobile telephone services differentiate themselves is by frequency. Each service is allocated a different frequency band in which to operate. The first mobile service offered in the U.S., and the one that is most commonly referred to as "cellular," operates in the 900 MHz band. The newer mobile service in the U.S., dubbed Personal Communications Service (or PCS), operates in the 1900 MHz band. In some cases, the only thing that separates "cellular" from PCS is the frequency band of operation. All other aspects of the technology are identical. (Of course the marketing people at the PCS companies don't want you to know that.) Table 7–1 is a summary of the frequency band allocations for some mobile services in the United States.
Table 7–1 Allocated Frequency Bands in the U.S.
System Mobile to Basestation Basestation to Mobile
Cellular 824–849 MHz 869–894 MHz
PCS 1850–1910 MHz 1930–1990 MHz
SMR 806–824 MHz 851–869 MHz
Another way these services differentiate themselves is by the technology used to transport the voice signal. The earliest mobile phone systems used analog voice signals, while the newer ones use digital. (In the not-too-distant future, I predict there will be no more analog systems.) In the case of the first cellular systems, the upgrade to digital technology used much of the existing infrastructure, including the assigned frequency bands. These new digital systems differentiate themselves by the modulation they use to encode the digital inf
You can generate a ton of business by networking, whether you belong to a networking organization or just get referrals from existing (satisfied) customers. Whenever you meet a new potential client, it’s important to create the right impression about you and your business straight away. That’s where a 10 second introduction comes in handy – and the more this introduction stands out from the rest, the more likely your new acquaintance is to remember you.One great way of making your introduction stand out and to really grab the attention of the person you’re introducing yourself to is to put an unexpected twist right at the start. One lady I know starts her introduction: “Hello, I’m Jane Doe, and I want to root through your trash cans.” Now that’s an introduction that nails everybody’s attention – and leaves the
A World of Choices
Differentiators There are many choices for mobile telephone service in the United States. Each of these systems has one or more distinguishing characteristics that differentiate it from the others. One of the most prominent ways that these mobile telephone services differentiate themselves is by frequency. Each service is allocated a different frequency band in which to operate. The first mobile service offered in the U.S., and the one that is most commonly referred to as "cellular," operates in the 900 MHz band. The newer mobile service in the U.S., dubbed Personal Communications Service (or PCS), operates in the 1900 MHz band. In some cases, the only thing that separates "cellular" from PCS is the frequency band of operation. All other aspects of the technology are identical. (Of course the marketing people at the PCS companies don't want you to know that.) Table 7–1 is a summary of the frequency band allocations for some mobile services in the United States.
Table 7–1 Allocated Frequency Bands in the U.S.
System Mobile to Basestation Basestation to Mobile
Cellular 824–849 MHz 869–894 MHz
PCS 1850–1910 MHz 1930–1990 MHz
SMR 806–824 MHz 851–869 MHz
Another way these services differentiate themselves is by the technology used to transport the voice signal. The earliest mobile phone systems used analog voice signals, while the newer ones use digital. (In the not-too-distant future, I predict there will be no more analog systems.) In the case of the first cellular systems, the upgrade to digital technology used much of the existing infrastructure, including the assigned frequency bands. These new digital systems differentiate themselves by the modulation they use to encode the digital inf
Today on the Internet we have hundreds of anti-everything type bloggers, who attack US policy, the World Bank and claim that we are the cause of the World’s ills. Not once will they blame the corruption of second tier nations or those of the third world. These bloggers yell; The US is killing women and children in Iraq and going to kill innocent life in Iran.Yet we all know that when dealing with fanatical, nut cases and dictators who slaughter their own people with WMD type weapons (Kurds). These Bloggers use of every possible media spin event against the Greatest Nation in the History of the Human Race; The United States of America and our leadership is truly telling.They complain about the World Bank, The USA and fail to admit how dishonest, unethical and the fanatical all these players are in these
Table 7–1 Allocated Frequency Bands in the U.S.
System Mobile to Basestation Basestation to Mobile
Cellular 824–849 MHz 869–894 MHz
PCS 1850–1910 MHz 1930–1990 MHz
SMR 806–824 MHz 851–869 MHz
Another way these services differentiate themselves is by the technology used to transport the voice signal. The earliest mobile phone systems used analog voice signals, while the newer ones use digital. (In the not-too-distant future, I predict there will be no more analog systems.) In the case of the first cellular systems, the upgrade to digital technology used much of the existing infrastructure, including the assigned frequency bands. These new digital systems differentiate themselves by the modulation they use to encode the digital inf
A Miniature ChipThe rectangular shaped thin card known as SIM CARD gives power to the phone notwithstanding the electric or battery energy conferred upon the handset. This miniature card allows mobile users get into the stream of cellular technology with all of the data stored on board the tiny chip. The information pertaining to phone number, contacts or phone book, mobile banking, messages, and other data is stockpiled on it.Changing NumberYour sim card brings you to the reach of the mobile service providers in your area to avail of its network benefits. Conversely, every network carrier generates its own sim card for use of the consumers who prefer prepaid plans. It holds your ID to the network to activate your phone and let you use a particular network. If for instance Verizon produces your s
Table 7–1 Allocated Frequency Bands in the U.S.
System Mobile to Basestation Basestation to Mobile
Cellular 824–849 MHz 869–894 MHz
PCS 1850–1910 MHz 1930–1990 MHz
SMR 806–824 MHz 851–869 MHz
Another way these services differentiate themselves is by the technology used to transport the voice signal. The earliest mobile phone systems used analog voice signals, while the newer ones use digital. (In the not-too-distant future, I predict there will be no more analog systems.) In the case of the first cellular systems, the upgrade to digital technology used much of the existing infrastructure, including the assigned frequency bands. These new digital systems differentiate themselves by the modulation they use to encode the digital information onto the RF carrier. Most use a form of phase modulation or QAM (discussed in Article 5). Mobile telephone services also differentiate themselves by something called air interface, which you will learn about shortly.
Some of these services differentiate themselves by offering additional features compared to "standard" mobile service. One of the lesser known mobile services available is something called Specialized Mobile Radio or SMR. SMR, which operates in two different frequency bands in the 800 MHz range in the U.S., was originally intended for use as a wireless dispatch service (think taxi cabs). Today, it has evolved into a combination dispatch and mobile phone service. This combination service distinguishes SMR from all the other mobile phone services available. Not only can the service be used to make "ordinary" mobile calls in the interconnected mode, it can also be used to conduct wireless teleconferencing in dispatch mode. In this mode, several people using the service can hold a conversation simultaneously. As such, SMR is popular with teams of mobile salespeople who need to conduct spontaneous sales meetings. Worldwide Systems
Just so you do not get the wrong idea, the United States is far from being the only place with mobile telephony. Table 7–2 shows some of the world's major mobile telephone systems. The first thing to notice is that there are a lot of different analog and digital technologies that have evolved over the years and none of them talk to each other.
Table 7–2 Worldwide Mobile Telephone Systems
Acronym System Where First Deployed Technology
AMPS Advanced Mobile Telephone Service United States Analog
CDMA Code Division Multiple Access United States Digital
D-AMPS Digital Advanced Mobile Telephone Service United States Digital
DCS1800 Digital Communication Service Germany & England Digital
GSM Group Special Mobile 80 European countries Digital
JTACS Japan Total Access Communications System Japan Analog
NADC North American Digital Cellular United States Digital
NMT Nordic Mobile Telephone Scandinavian countries Analog
PCS1900 Personal Communications Services United States Digital
PDC Personal Digital Cellular Japan Digital
SMR Specialized Mobile Radio United States Both
TACS Total Access Communications System England Analog
HTTP = HTML link (for blogs, profiles,phorums):
<a href="http://www.memberyou.net/article/175459/memberyou-Mobile-Telephony.html">Mobile Telephony</a>
BB link (for phorums):
[url=http://www.memberyou.net/article/175459/memberyou-Mobile-Telephony.html]Mobile Telephony[/url]
Related Articles:
The Newest Advancement in Training for Truck Driving
Business Etiquette For Letters & Emails
Card Debt Negotiation Reducing Your Credit Card Debt
Bookmark it:
|