BTS Installation & Commissioning Under GP Swap

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BTS Installation & Commissioning Under GP Swap

1 Introduction:

Telecommunication is the transmission of information over significant distances to communicate. In earlier times, telecommunications involved the use of visual signals, such as beacons, smoke signals, semaphore telegraphs, signal flags, and optical heliographs, or audio messages via coded drumbeats, lung-blown horns, or sent by loud whistles, for example. In the modern age of electricity and electronics, telecommunications now also includes the use of electrical devices such as telegraphs, telephones, and teleprompters, the use of radio and microwave communications, as well as fiber optics and their associated electronics, plus the use of the orbiting satellites and the Internet.


Short for Global System for Mobile Communications, GSM is a digital cellular communications system. It was developed in order to create a common European mobile telephone standard but it has been rapidly accepted worldwide. GSM is designed to provide a comprehensive range of services and features to the users not available on analogue cellular networks and in many cases very much in advance of the old public switched telephone network (PSTN). In addition to digital transmission, GSM incorporates many advanced services and features like worldwide roaming in other GSM networks.


1.1.1 Architecture of the GSM Network:

The GSM mobile telephony service is based on a series of contiguous radio cells which provide complete coverage of the service area and allow the subscriber operation anywhere within it. Prior to this cellular concept, radiophones were limited to just the one transmitter covering the whole service area. Cellular telephony differs from the radiophone service because instead of one large transmitter, many small ones are used to cover the same area. The basic problem is to handle the situation where a person using the phone in one cell moves out of range of that cell. In the radiophone service there was no solution and the call was lost, which is why the service area was so large. In cellular telephony, handing the call over to the next cell solves the problem. This process is totally automatic and requires no special intervention by the user, but it is a complex technical function requiring significant processing power to achieve a quick reaction.

The functional architecture of a GSM system can be broadly divided into the Mobile Station, the Base Station Subsystem, and the Network Subsystem. Each subsystem is comprised of functional entities that communicate through the various interfaces using specified protocols. The subscriber carries the mobile station; the base station subsystem controls the radio link with the Mobile Station. The network subsystem, which is the main part of which is the Mobile services Switching Center, performs the switching of calls between the mobile and other fixed or mobile network users, as well as management of mobile services, such as authentication.

Figure 1.1: GSM Network Overview.

1.2 Mobile Telephone System

Figure 1.2: Ericsson GSM System

The Base Station System (BSS) contains two functional entities; the Base Station Controller (BSC) and the Base Transceiver Station (BTS). The BSC handles radio-related functions, such as handover, management of the radio network resources, and cell configuration data. It also controls radio Frequency power levels in RBSs and MSs. The BTS is a network component which serves one cell and is controlled by the BSC. The BTS contains a number of transceivers. It consists of the radio transceivers and all the digital signal processing equipment. RBS 2106 contains equipment for 1 – 3 BTSs.

1.3 Radio Base Station

The Radio Base Station 2106 (RBS 2106) is Ericsson’s second generation of RBSs developed to meet the GSM specifications for BTSs.

1.3.1Base Station Subsystem:

The Base Station Subsystem is composed of two parts, the Base Transceiver Station (BTS) and the Base Station Controller (BSC). The BTS houses the radio transceivers that define a cell and transmits and receives signals on the cells’ allocated frequencies with the mobile station.

A BSC operates with a group of BTSs and manages the radio resources for one or more of them. The BSC is the connection between the MS and the Network Subsystem. It manages the radio channel (setup, tear down, frequency hopping, etc.) as well as handovers and the transmission power levels and frequency translations of the voice channel used over the radio link to the standard channel used by the Public Switched Telephone Network or ISDN.

1.3.2 Network Subsystem:

The central component of the Network Subsystem is the Mobile services Switching Center (MSC). It acts like a normal switching node of the normal telephones of the land lines and in addition provides all the functionality needed to handle a mobile subscriber, including registration, authentication, location updating and inter-MSC handovers. These services are provided in conjunction with several functional entities, which together form the Network Subsystem. The MSC provides the connection to the public fixed network (PSTN or ISDN) and is the interface between the GSM and the PSTN networks for both telephony and data.

Thus the MSC is primarily responsible for:

Traffic management

Call set-up

Call Routing to a roaming subscriber


Charging and accounting information

2 RBS Types:

2.1RBS 2106

Figure 2.1: RBS 2106

The RBS 2000 family supports a wide range of applications ranging from extreme coverage to extreme capacity. Being a RBS 2000 member guarantees coexistence with the installed base of RBS 200 and RBS 2000 products. RBS 2106 Outdoor cabinet with a maximum of six dTRUs/12 TRXs per cabinet Ericson’s synchronization based BSS features ensure that transceivers from different generations of radio base stations can easily form common cells. Operators can therefore bridge the past with the future. By making existing sites future proof, investments are protected while migrating to 3G.RBS 2106 is a high capacity, compact outdoor macro radio base station supporting up to twelve transceivers per cabinet. It is possible to build one, two and three sector configurations including dual band configurations in one cabinet. Being the latest member in the RBS 2000 family, RBS 2106 is to date the most powerful outdoor RBS in the world. Keeping the successful characteristics of the existing RBS 2000 portfolio and improving functionality as well as operation and maintenance makes the RBS 2106 a very cost-effective solution for growing GSM operators.

2.1.1 Part of the grow-on-site concept

Since it is becoming increasingly difficult to find newbase station sites, it is of great interest to remain on theexisting sites as long as possible. Site space is often alimiting factor for capacity growth. The powerful RBS2106, included in Ericson’s grow-on-site toolbox, addresses this problem. On many sites, two or moreexisting cabinets can be replaced by one RBS 2106.This is of major importance, since it makes it possibleto reuse the space to rollout WCDMA equipment. TheRBS 2106 will pave the way for WCDMA.Also interesting for new locations; the RBS 2106 offersa complete solution in stand-alone cabinet whichrapidly can be implemented outdoors.

2.1.2 RBS 2106 (Outdoor environment) — Macro-BTS Key features

Six double transceiver units (dTRU); 12 transceivers in total

Filter and hybrid combining one, two, or three cabinets

Excellent RF performance

Synthesized and baseband frequency hopping

Supports 12 transceiver EDGE on all timeslots

Supports GSM 800, 900, 1800 and 1900 MHz

Extended Range 121 km

Duplexer and TMA support for all configurations

Four transmission ports supporting up to 8 Mbps

Optional built-in transmission equipment

Prepared for GPS assisted positioning services

For installation For create IDB

CDU G18 to CDU G9 Frequency =GSM 900

dTRU 18 to dTRU 9 input voltage=AC 200-250v

GSM 1800 to GSM 900 TRx Configuration = 3×4

2.2 RBS 2116 V2

A Member of the RBS 2000 Family. As a member of the world-leading RBS 2000 family, the RBS 2116 V2 continues the tradition of excellent-coverage base stations from Ericsson by bringing the RBS 2116 closer to the RBS 2106 V3. This means, for example, using the same replaceable units, such as power supply units, in both the RBS 2116 V2 and the RBS 2106 V3.From hereon in this document the RBS 2116 V2 is referred to as the RBS 2116.Reducing the Total Cost of Ownership (TCO) to capture revenue in new growth markets requires reducing both capital and operating expenses to levels not previously seen in the industry. Whether your growth markets require broader coverage, increased capacity, or enhanced quality, the RBS 2116 is designed to deliver the higher performance, faster time to service, and greater simplicity essential in minimizing TCO. With its unique understanding of all the cost elements associated with operating cellular networks, Ericsson is now taking the world’s most successful base station platform one step further to deliver products that will set the new standard for the continued evolution of GSM and WCDMA

Figure 2.2:RBS 2116V2

2.2.1 Architecture

The RBS 2116 includes the following types of replaceable units:

•Alternating Current Connection Unit (ACCU)

•Battery Fuse Unit (BFU)

•DC/DC power converter for transmission space

•Direct Current Connection Unit (DCCU)

•Distribution Switch Unit (DXU)

•Door with heat exchanger and fans

• Double Radio Unit (DRU)

•Fan Connection Board (FCB) and fan unit

•Internal Distribution Module (IDM)

•Overvoltage Protection (OVP) module

•Power Supply Unit (PSU)

•Receiver (RX) splitter

•Tower-Mounted Amplifier Control Module (TMA-CM)

FOR installation For create IDB

GSM1800 –to-GSM900&1800 Frequency =GSM900 and GSM 1800

DRU 18 –to-DRU 9 input Voltage=AC 200-250v

TRx Configuration = 3×2|3×2



An antenna is a transducer designed to transmit or receive electromagnetic waves. In other words, antennas convert electromagnetic waves into electrical current and vice versa. Antennas are used in systems such as radio and television broadcasting, point-to-point radio communication, wireless LAN, radar, and space exploration. Antennas usually work in air or outer space, but can also be operated under water or even through soil and rock at certain frequencies for short distances.

3.1.1 Antennas Resonant

While there are broadband designs for antennas, the vast majority of antennas are based on the half-wave dipole which has a particular resonant frequency. At its resonant frequency, the wavelength is slightly over twice the length of the half-wave dipole . The quarter-wave vertical antenna consists of one arm of a half-wave dipole, with the other arm replaced by a connection to ground or an equivalent ground plane. A Yagi-Uda array consists of a number of resonant dipole elements, only one of which is directly connected to the transmission line. The quarter-wave elements of a dipole or vertical antenna imitate a series-resonant electrical element, since if they are driven at the resonant frequency a standing wave is created with the peak current at the feed-point and the peak voltage at the far end.

3.1.2 Antennas Current and voltage distribution

The antenna conductors have the lowest feed-point impedance at the resonant frequency where they are just under 1/4 wavelength long; two such conductors in line fed differentially thus realize the familiar “half-wave dipole”. When fed with an RF current at the resonant frequency, the quarter wave element contains a standing wave with the voltage and current largely (but not exactly) in phase quadrature, as would be obtained using a quarter wave stub of transmission line. The current reaches a minimum at the end of the element (where it has nowhere to go!) and is maximum at the feed-point. The voltage, on the other hand, is the greatest at the end of the conductor and reaches a minimum (but not zero) at the feed point. Making the conductor shorter or longer than 1/4 wavelength means that the voltage pattern reaches its minimum somewhere beyond the feed-point, so that the feed-point has a higher voltage and thus sees a higher impedance, as we have noted. Since that voltage pattern is almost in phase quadrature with the current, the impedance seen at the feed-point is not only much higher but mainly reactive.

3.1.3 Antennas Bandwidth

Although a resonant antenna has a purely resistive feed-point impedance at a particular frequency, many (if not most) applications require using an antenna over a range of frequencies. An antenna’s bandwidth specifies the range of frequencies over which its performance does not suffer due a poor impedance match. Also in the case of a Yagi-Uda array, the use of the antenna very far away from its design frequency reduces the antenna’s directivity, thus reducing the usable bandwidth regardless of impedance matching.

3.1.4 Antennas Gain

Gain is a parameter which measures the degree of directivity of the antenna’s radiation pattern. A high-gain antenna will preferentially radiate in a particular direction. Specifically, the antenna gain, or power gain of an antenna is defined as the ratio of the intensity (power per unit surface) radiated by the antenna in the direction of its maximum output, at an arbitrary distance, divided by the intensity radiated at the same distance by a hypothetical isotropic antenna.

The gain of an antenna is a passive phenomenon – power is not added by the antenna, but simply redistributed to provide more radiated power in a certain direction than would be transmitted by an isotropic antenna. An antenna designer must take into account the application for the antenna when determining the gain. High-gain antennas have the advantage of longer range and better signal quality, but must be aimed carefully in a particular direction. Low-gain antennas have shorter range, but the orientation of the antenna is relatively inconsequential. For example, a dish antenna on a spacecraft is a high-gain device that must be pointed at the planet to be effective, whereas a typical Wi-Fi antenna in a laptop computer is low-gain, and as long as the base station is within range, the antenna can be in any orientation in space. It makes sense to improve horizontal range at the expense of reception above or below the antenna. Thus most antennas labelled “omnidirectional” really have some gain.<href=”#cite_note-4″>[5]

In practice, the half-wave dipole is taken as a reference instead of the isotropic radiator. The gain is then given in dBd (decibels over dipole):

NOTE: 0 dBd = 2.15 dBi. It is vital in expressing gain values that the reference point be included. Failure to do so can lead to confusion and error.

3.1.5 Antenna Effective area or aperture

The effective area or effective aperture of a receiving antenna expresses the portion of the power of a passing electromagnetic wave which it delivers to its terminals, expressed in terms of an equivalent area. For instance, if a radio wave passing a given location has a flux of 1 pW / m2 (10?12 watts per square meter) and an antenna has an effective area of 12 m2, then the antenna would deliver 12 pW of RF power to the receiver (30 microvolts rms at 75 ohms). Since the receiving antenna is not equally sensitive to signals received from all directions, the effective area is a function of the direction to the source.

Due to reciprocity (discussed above) the gain of an antenna used for transmitting must be proportional to its effective area when used for receiving. Consider an antenna with no loss, that is, one whose electrical efficiency is 100%. It can be shown that its effective area averaged over all directions must be equal to ?2/4?, the wavelength squared divided by 4?. Gain is defined such that the average gain over all directions for an antenna with 100% electrical efficiency is equal to 1. Therefore the effective area Aeff in terms of the gain G in a given direction is given by:

For an antenna with an efficiency of less than 100%, both the effective area and gain are reduced by that same amount. Therefore the above relationship between gain and effective area still holds. These are thus two different ways of expressing the same quantity. Aeff is especially convenient when computing the power that would be received by an antenna of a specified gain, as illustrated by the above example.

3.1.6 Antennas Radiation pattern

Figure 3.1:Polar plots of the horizontal cross sections of a (virtual) Yagi-Uda-antenna

The radiation pattern of an antenna is a plot of the relative field strength of the radio waves emitted by the antenna at different angles. It is typically represented by a three dimensional graph, or polar plots of the horizontal and vertical cross sections. The pattern of an ideal isotropic antenna, which radiates equally in all directions, would look like a sphere. Many nondirectional antennas, such as monopoles and dipoles, emit equal power in all horizontal directions, with the power dropping off at higher and lower angles; this is called an omnidirectional pattern and when plotted looks like a torus or donut.

3.1.7 Antennas Impedance

As an electro-magnetic wave travels through the different parts of the antenna system (radio, feed line, antenna, free space) it may encounter differences in impedance (E/H, V/I, etc.). At each interface, depending on the impedance match, some fraction of the wave’s energy will reflect back to the source,<href=”#cite_note-5″>[6] forming a standing wave in the feed line. The ratio of maximum power to minimum power in the wave can be measured and is called the standing wave ratio (SWR). A SWR of 1:1 is ideal. A SWR of 1.5:1 is considered to be marginally acceptable in low power applications where power loss is more critical, although an SWR as high as 6:1 may still be usable with the right equipment. Minimizing impedance differences at each interface (impedance matching) will reduce SWR and maximize power transfer through each part of the antenna system.

3.2 Microwave Antenna

Since the operating principles of low-frequency and microwave antennas are essentially the same, the electrical characteristics are also very similar. I shall need a fundamental knowledge of radar and communications antenna electrical theory in my shipboard antenna maintenance work. Antenna theory is primarily a design consideration of antenna size and shape requirements that depend on the frequency used. A brief description of antenna electrical characteristics is sufficient for the needs of most students of electronics.

Figure 3.2: Microwave Antenna

3.2.1 Microwave transmission

Microwave transmission refers to the technology of transmitting information or power by the use of radio waves whose wavelengths are conveniently measured in small numbers of centimeters; these are called microwaves. This part of the radio spectrum ranges across frequencies of roughly 1.0 gigahertz (GHz) to 30 GHz. These correspond to wavelengths from 30 centimeters down to 1.0 cm.

Microwaves are widely used for point-to-point communications because their small wavelength allows conveniently-sized antennas to direct them in narrow beams, which can be pointed directly at the receiving antenna. This allows nearby microwave equipment to use the same frequencies without interfering with each other, as lower frequency radio waves do. Another advantage is that the high frequency of microwaves gives the microwave band a very large information-carrying capacity; the microwave band has a bandwidth 30 times that of all the rest of the radio spectrum below it. A disadvantage is that microwaves are limited to line of sight propagation; they cannot pass around hills or mountains as lower frequency radio waves can.

Microwave radio transmission is commonly used in point-to-point communication systems on the surface of the Earth, in satellite communications, and in deep space radio communications. Other parts of the microwave radio band are used for radars, radio navigation systems, sensor systems, and radio astronomy.

3.3 GSM Antenna

Our Base Station Antennas are including 806-896MHz Dual Polarization Directional Panel Antennas,806-896MHz Directional Panel Antennas,870-960MHz Dual Polarization Directional Panel Antennas,870-960MHz Directional Panel Antennas,824-960MHz Dual Polarization Directional Panel Antennas,824-960MHz Directional Panel Antennas, 1710-2170MHz Dual Polarization Directional Panel Antennas, 1710~2170MHz Directional Panel Antennas, 1710-1880MHz Dual Polarization Directional Panel Antennas,870-960/1710-1880MHz Dual-band Directional Panel Antennas,824-960/1710-2170MHz Dual-band Directional Panel Antennas,1710-2170MHz 2*Dual-band Directional Panel Antennas.

Figure 3.3: Gsm Antenna

Features Single band GSM 900/1800 MHz

Size 64.5mm(D) x 14mm(H)

Frequency 880~960 & 1710~1880 MHz

Gain 1.7 dBi

Band Width


— 170 MHz for frequency of 1710~1880 MHz

VSWR < 1.5

Impedance 50 ohm

Power Supply Power Handling Capacity: 10 W

3.4 Base Transceiver Station (BTS)

A BTS is a unit operating on a set of frequencies in one cell.

3.4.1Basic Configuration

A basic configuration is a specified set of transceivers, CDUs, and in some

cases, TMAs, connected to one antenna system.

A basic configuration can be multiplied or used in combination with other basic

configurations to build the needed site equipment.

Variations of a basic configuration may exist, differing in cable lengths. This

depends on factors such as implementation in different cabinets.

3.4.2 Radio Base Station (RBS)

An RBS is all equipment in an Ericsson base station, and may be comprised

of several BTSs.

Each RBS has one DXU, controlling a maximum of 12 TRXs.

in three sectors, that is three distinct

areas, using three BTSs.

3.4.3 Frequency Bands

GSM 800 Uplink: 824 – 849 MHz

Downlink: 869 – 894 MHz

P-GSM 900 Uplink: 890 – 915 MHz

Downlink: 935 – 960 MHz

E-GSM 900 Uplink: 880 – 915 MHz

Downlink: 925 – 960 MHz

GSM 1800 Uplink: 1710 – 1785 MHz

Downlink: 1805 – 1880 MHz

GSM 1900 Uplink: 1850 – 1910 MHz

DTRU Topology

4.1 Configuration of Hybrid Combiner

The dTRU can be configured with or without the hybrid combiner, using two external cables.

4.1.1 RX Signals Distributed from Two Ports

The RX signals can be distributed from the RX1 and RX2 ports to all fourreceivers when both transceivers are connected to the same antenna system.

Figure 4.1: DTRU with and without hybrid combiner in use

4.1.2 Ericsson DTRU 1800MHz

4.1.3 KRC1311003/2

Name/Model: Ericsson KRC1311003/2 DTRU DCS (RBS2X06) EDGE
Manufacturer part number: KRC1311003/2
Description: Ericsson KRC1311003/2 DTRU DCS (RBS2X06) EDGE rbs2000
Manufacturer: Ericsson
Condition: Refurbished
Warranty: 90 days
Number available: 100
Ex works: Germany

Figure4.2: Double Transceiver Ericsson DTRU-18 used refurbished,

4.2 CDU Combining and Distribution Unit

The CDU is the interface between the transceivers and the antenna system. All signals are filtered before transmission and after reception by means of band pass filters. The CDU allows several dTRUs to share antennas. There are a maximum of three CDUs in one RBS 2106.The CDU combines transmitted signals from several transceivers, and distributes the received signal to several transceivers. The CDU is hardware-prepared to support EDGE. Two different CDU types are used in the RBS 2106 to support all configurations:

•CDU-F is a filter combiner intended for high capacity solutions.

• CDU-G can be configured either for high capacity or for high coverage

It is a combiner that can be used for synthesizer hopping.

Number of units: 1 – 3

The various con?guration available for cabinets are described using the following system: In the example above, the cabinet is ?tted with 3 CDUs, each connected to 2 TRUs; so there is a total of 6 TRUs in this case. The CDU is type CDU-F. The RF cables between each CDU and its associated TRUs are standardized and do not normally change. Each CDU uses a set of standard RF wiring patterns for connection between each CDU and the cabinet Connection Field. In the gores and tables in the sections that follow, the cabinets shown are fully equipped. The con?guration consisting of a part of the fully equipped cabinet are also possible to extract.

Figure4.3 :(1*4)CDU-F

4.3 Site Cell Configurations (SCC)

This section shows SCCs in one RBS. More RBSs can be combined to form larger configurations at a site. Possible expansions, where different RBSs are connected using TG synchronization.

The following SCCs are supported by the RBS:

• Specified basic radio configurations

• The RBS with any number of dTRUs within the specified range inserted in the specified position order.

4.3.1 Site Cell Configuration (SCC)

The SCC is a geographical concept describing how an area around one RBS

site is divided into radio traffic areas. The following types of site are defined:

Omni-site Radio coverage in one 360 degree sector, that is in

one area, using one BTS.

2-sector site Radio coverage in two sectors, which is two distinct

areas, using two BTSs.

3-sector site Radio coverage

Single Band Configurations

This section describes single band configurations for CDU-F and CDU-G.

4.3.2 CDU-F Single Band Configurations

Figure4.4: CDU-F & CDU-G


5 Commissioning and Installation:

5.1 Mini link

MINI-LINK CN is optimized for end sites, single hops, and enterprise. There are a number of MINI-LINK CN products, for example, MINI-LINK CN 210, MINI-LINK CN 500 and MINI-LINK CN 510. Each of them is easy to install, and is specifically optimized for a certain type of site.

Figure 5.1: MINILINK

It is done by the MINI LINK soft.

Figure 5.2: Mini link soft update

Figure 5.3: Starting for update the RBS

Figure 5.4: TN Load Configuration

Figure 5.5: Check the view units

Figure 5.6: Configure the baseline & module

Figure 5.7: Settings

Figure 5.8: Start Update

Figure 5.9: Check all settings

Figure 5.10: Updating the Module

We find the final confirmation massage from end of this FIGURE,.

Figure 5.11: Confirm the soft activation

5.2 OMT Software system:

It is used for local and remote monitoring control of RBS. We see the condition of the RBS both outdoor work and software in our PC or Laptop. Support SMS and GPRS communication. Support polling function that’s usually with complicated OMC system.

Figure 5.12: OMT load

When we see that there is no alarm in display then we say that the RBS running successful.

Figure 5.13 Confirmmation of OMT

5.3 E1 Connecting:

E1 is a differential communications interface using either two pairs (TX and RX) connected through a single RJ-48C connector (also frequently written as RJ48, RJ-48 or RJ48c and also often incorrectly called RJ-45 or RJ45 – it is an RJ connector with 8 contacts assigned according to specification RJ-48C) or using two coaxial connections (TX and RX) via two BNC connectors. To enable reliable transmission and reception over 1000s of metres of cable between customer premises and telephone exchanges, the data is encoded using HDB3 to produce a bipolar signal with the required characteristics. Note that timing information (i.e. the bit clock) is encoded within the signal to enable the receiver to recover a clock and correctly decode the received data.

Figure 5.14: E1 Connecting

Figure 5.15:E1 color code

Alarming and VSWR:

6.1 Alarm:

In Ericsson there are used some alarm that work in a sequence. The sequence are given below,

Figure 6.1: Alarm Color Code

Figure 6.2: External Alarm Cable RBS 2116

Figure 6.3: Transmission Cable (E1) DXU to OVP RBS 2116


VSWR, or voltage standing wave ratio, is a measure of how well the components of the RF network are matched in impedance. When the impedances are improperly matched, you lose signal power, which results in weak transmissions, poor reception or both. Maximum power transfer between two system components occurs when their respective impedances are matched. If the impedances are not identical, some RF power will be reflected back, resulting in a reduction in the amount of power delivered to the load. These reflections cause voltage standing waves.

There are two way to measure VSWR.

By Hardware with Site Master.

Figure 6.4: Site Master

By Software with MINILINK.

Figure 6.5: By MINILINK SOFT

6.3 Feeder Cable (Coax cable)

Coax cable, coaxial feeder is normally seen as a thick electrical cable. The cable is made from a number of different elements that when together enable the coax cable to carry the radio frequency signals with a low level of loss from one location to another. The main elements within a coax cable are:

1.Centre conductor

2.Insulating dielectric

3.Outer conductorOuter

4.protecting jacket or sheath

The overall construction of the coax cable or RF cable can be seen in the diagram below and from this it can be seen that it is built up from a number of concentric layers. Although there are many varieties of coax cable, the basic overall construction remains the same:

Figure 6.6: Feeder Cable

Figure 6.7: Feeder Cable Indoor

6.4 Battery Fuse Unit

The BFU supervises the batteries in external BBS products and can also supply the transmission equipment with prioritized +24 V DC backup power. Number of units: 0–1

DC/DC Converters

The DC/DC converters are optional equipment that can supply

?48 V DC to equipment with a power rating of up to 400 W installed in the transmission space. Number of units: 0–2

3.12 Battery Backup

The BBS 2116 is an ideal backup solution that can supply backup power to two RBS 2116 cabinets simultaneously. The cabinet matches the RBS 2116 in size and has room for a large battery capacity. The optional climate system ensures that the battery is kept at the right temperature to prolong long battery life .The BBS 2116 is also compatible with most Ericsson outdoor RBS cabinets, such as the RBS 2106i, RBS 2106 V3, RBS 3106, and RBS 3116.Alternative backup systems for the RBS 2116 include the BBS 8500 and BBS 8500C.


A large amount of today’s telecommunication consists of mobile and short distance wireless applications, where the effect of the channel is unknown and changing over time, and thus needs to be described statistically. Therefore the received signal can not be accurately predicted and has to be estimated.

Modern biotechnology and IT have received much attention, due to their perceived importance in stimulating innovation-led growth. Indeed, many readers likely already have ideas about the lessons which ‘everyone knows’ should be drawn from biotechnology and telecommunication. To stimulate biotech, you need lots of basic science, small companies some venture capital, and outstanding science-based ideas that sell on the world market. To stimulate telecommunication systems, you need a big company which is leading in a range of technologies, competent bureaucrats and/or operators to define future directions for innovation, and users which come up with new, unexpected uses for the hardware. Many practitioners have set out to act upon such recommendations, leading to strategic moves by both government policy-makers and firm leaders. This ‘accepted’ interpretation may be largely correct. Yet we would argue that this special issue provides somewhat different lessons, which may challenge ‘accepted truths’. This section will consider general remarks in terms of the three themes discussed in the introduction as well as specific implications from each article, in turn.


Ericsson, Fundamentals of Microwave Applied Theory.

Antennas (3rd edition), by J. Kraus and R. Marhefka, McGraw-Hill, 2001.

Siemens, Microwave Company, Unpublished.

Siemens GSM Manual.

Ericsson Telecom equipment.

Huawei, Site Master Equipment.

Airtel Bangladesh Website.

Matthew M. Radmanesh, 1942, Radio Frequency & Microwave Electronics Mc-Graw Hill.