3G Wireless Networks

This section is meant to describe the coverage quality requirements for the system. The coverage quality is a series of parameters that will be used to clearly define the link budget requirements for the system and the geographic areas within ... [full story]

Numerous mobile wireless systems have been deployed throughout the world. Each of the various 1G wireless systems has its own unique advantage and disadvantages, depending on the spectrum available and the services envisioned for delivery. 1G mobility systems are ... [full story]

Although the advancement of technology (any technology) certainly involves quantum leaps forward from time to time, it is common for major progress to also occur as a result of incremental improvements. For mobile communications technology, advancement has come about in ... [full story]

This chapter has served as a brief introduction to mobile communications systems. The brief overview that has been given, however, is certainly not a sufficient background to enable a good understanding of third-generation technology. Therefore, before tackling the details of ... [full story]

Harmonization refers to the vision and objective of the IMT2000 specification that enables the various technology platforms that are defined in that specification to interact with each other. True harmonization relative to the capability of a CDMA2000 and WCDMA system ... [full story]

In the previous sections of this chapter, some of the various technology platforms were discussed. The existing wireless operators today, regardless of the frequency band or existing technology deployed have or are making very fundamental decisions as to which direction ... [full story]

Handoff (also known as handover) is the ability of a subscriber to maintain a call while moving within the network. The term handoff is typically used with AMPS, IS-136, and IS-95, while handover is used in GSM. The two terms ... [full story]

The discussion so far has focused largely on the methods used to access the network over the air interface. The air interface access is, of course, extremely important. Other aspects, however, are necessary in order to make a wireless communications ... [full story]

With CDMA, neither the time domain nor the frequency domain are subdivided. Rather, all users share the same radio frequency at the same time. This approach obviously means that all users interfere with each other. Such interference would be intolerable ... [full story]

With Time Division Multiple Access (TDMA), radio channels are divided into a number of time slots, with each user assigned a given timeslot. For example, on a given radio frequency, user A might be assigned timeslot number 1 and user ... [full story]

Of the common multiple access techniques used in mobile communications systems,FDMA is the simplest.With FDMA, the available spectrum is divided into a number of radio channels of a specified bandwidth, and a selection of these channels is used within a ... [full story]

Radio spectrum is a precious and finite resource. Unlike other transmission media such as copper or fiber facilities, it is not possible to simply add radio spectrum when needed. Only a certain amount of spectrum is available and it is ... [full story]

Figure 1-6 shows a typical (although very basic) mobile communications network. A number of base stations are connected to a Base Station Controller (BSC). The BSC contains logic to control each of the base stations. Among other tasks, the BSC ... [full story]

Even though the term “cellular” is often used in North America to denote analog AMPS systems, most, though not all, mobile communications systems are cellular in nature. Cellular simply means that the network is divided into a number of cells, ... [full story]

In many ways, second-generation systems have come about because of fundamental weaknesses in first-generation technologies. First-generation technologies have limited system capacity, they have very little protection against fraud, they are subject to easy eavesdropping, and they have little to offer ... [full story]

Although they have significant differences, both IS- 136 and GSM use Time Division Multiple Access (TDMA). This means that individual radio channels are divided into timeslots, enabling a number of users to share a single RF channel on a time-sharing ... [full story]

Although NMT had been introduced in Europe as recently as 1981, the Europeans soon recognized the need for a pan-European digital system. There were many reasons for this, but a major reason was the fact that multiple incompatible analog systems ... [full story]

 IS-136 came about through a two-stage evolution from analog AMPS. As described in more detail later, AMPS is a frequency division multiple access (FDMA) system, with each channel occupying 30 KHz. Some of the channels, known as control channels, are ... [full story]

Unlike first-generation systems, which are analog, second-generation systems are digital. The use of digital technology has a number of advantages, including increased capacity, greater security against fraud, and more advanced services. Like first-generation systems, various types of second-generation technology have ... [full story]

Mobile communications as we know it today really started in the late 1970s, with the implementation of a trial system in Chicago in 1978. The system used a technology known as Advanced Mobile Phone Service (AMPS), operating in the 800-MHz ... [full story]

Mobile telephony dates back to 1920s, when several police departments in the United States began to use radiotelephony, albeit on an experimental basis. Although the technology at the time had had some success with maritime vessels, it was not particularly ... [full story]

Over recent years, telecommunications has been a fast-growing industry. This growth can be seen in the increasing revenues of major telecommunications carriers and the continued entry into the marketplace of new competitive carriers. No segment of the industry, however, has ... [full story]

This section is meant to describe the coverage objectives for the system. The following are suggested points that need to be covered in this section: ■ What is the current coverage of the system? ■ What are the coverage requirements? ... [full story]

As with any good effort, the results need to be documented and communicated to the respective parts of the wireless organization. The following is a proposed guideline that can be used to help construct such a report. The report is ... [full story]

EMF compliance needs to be factored into the design process and the continued operation of the communication facility. The use of a EMF budget is strongly recommendedand can ensure personnel safety and government compliance. A simple source for the EMF ... [full story]

The activation of a cell site into the network is exciting. It is at this point that the determination is made for how effective the design of the cell site is in resolving the problem area. Numerous steps must be ... [full story]

In the unfortunate event that a potential site has been tested and is determined not to be suitable for a potential use in the network, a site rejection (SR) form needs to be filled out. The issuance of an SR ... [full story]

Once a site has been tested for its potential use in the network, it is determined to either be acceptable or not acceptable. For this section, the assumption will be that the site is acceptable for use by the RF ... [full story]

The Site Qualification Test (SQT) is an integral part of any RF system design. Even in the age of massive computer modeling, it is still essential that every system has some form of transmitter or site qualification test conducted. The ... [full story]

The definition of a search area and the information content provided is a critical first step in the cell site design process. The search area request is a key source document that is used by the real estate acquisition department ... [full story]

Although this is not necessarily the first step in any design process, it is one of the most important for the RF Engineering department. The reason the cell site design is critical lies in the fact it is where the ... [full story]

No true RF engineering can take place without some RF design guidelines, whether formal or informal. However, with the level of complexity introduced when integrating a 2.5G or 3G platform into an existing system, the need for a clear definitive ... [full story]