It helps in Types of mobile tower, height, operation, cellular structure, generation network, GSM, Accessing technique...

1. OPERATION-CUM-
TOWER
TECHNICIAN
Sector: TELECOM
Occupation: Operation & maintenance

2. CONTENT
 Objective
 Introduction
 Types of mobile tower
Definition of tower
Different tower pictures
 Telecom tower companies
In India
 Role and Responsibilities of site technician
 Components of tower site

3. Cont…
 Components within the Shelter
 Components within the diesel generator
 Cellular network
 Why external cell is used
 Merits and demerits of hexagonal cell
 Sectoring and process
 Multiple access techniques
 Generation of network (0G, 1G, 2G, 2.5G, 3G, 3.5G, 4G,
5G)
Mobile pictures of each generation of network

4. Cont…
 GSM communication
 Introduction to GSM
 History of GSM
 Why we go for GSM system
 GSM architecture
 Frequency band of GSM
 Uplink and downlink frequency
 Forward and reverse
 Extended GSM
 GSM architecture description
 Handover/ handoff process
GSM channel and
Single path and multi path

5. Architecture of 3G network
UMTS
4G architecture network
LTP
LTE
MIMO system
OFDM block diagram
Single carrier
Multi carrier
Different heights of tower
 LOC
 What are the obstacles to oppose the LOC

6. OBJECTIVE
To understand details about mobile towers.
To study about different types of mobile tower.
To study about Shelter.
To study about Diesel Generator.

7. WELCOME & INTRODUCTION
A cell site or cell tower is a cellular telephone site
where antennae and electronic communications equipment are
placed, usually on a radio mast, tower or other high place, to
create a cell (or adjacent cells) in a cellular network.
Frequency reuse – same frequency in
many cell sites
Cellular expansion – easy to add new cells
Handover – moving between cells
Roaming- between networks

8. Cont…
The safety of cell phone towers is the subject of extensive
scientific debate.
There is a growing body of scientific evidence that the
electromagnetic radiation they emit, even at low levels, is
dangerous to human health.
Radiation from mobile phones and towers has become a
significant risk to public health in urban hubs and cities

9. HISTORY
First telephone (photo phone) – Alexander Bell, 1880
The first car mounted radio telephone – 1921
1946 – First commercial mobile radio-telephone service by Bell
and AT&T in Saint Louis, USA. Half duplex(PTT)
1973 – First handheld cellular phone – Motorola.
1982 „Groupe Spécial Mobile” is created within CEPT
(Conférence Européenne des Postes et Télécommunications)
1987 Main Radio transmission techniques are chosen, based on
prototype evaluation (1986)
1989 GSM becomes an ETSI technical committee
1990 The Phase I GSM900 specification are frozen
DCS1800 adaptation starts
1991 First systems are running
DCS 1800 specifications are frozen
1992 All major European GSM 900 operators begin commercial
operations (2G)
2000 3G system comes in to market.
2010 4G system comes in to market.

10. TYPES OF MOBILE TOWER
1. Lattice Tower
 It is also referred to as a self-
supporting tower.
 The lattice tower affords the
greatest flexibility and is
often used in heavy loading
conditions.
 It is typically three or four
sided, with similar shaped
bases.

11. Cont…
2. Monopole Tower
 It uses minimal space and
resemble a single tube.
 It requires one foundation and
typically don't exceed 50m.
 The antennas are mounted on the
exterior of the tower.

12. Cont…
3. Guyed Tower
 Guyed towers used to be the cheapest tower
to construct, but require the greatest amount
of land.
 For taller heights (100 metres and greater) it
is much cheaper to build a guyed tower.
 Most radio and television towers are guyed
towers.
 A guyed tower is a straight tower (also
referred to as mast) connected by guy wires
attached to the ground in all directions,
which anchor and support the tower.

13. Cont…
4. Stealth Tower
 Stealth towers are typically
required by councils and at times,
owners.
 They are always more expensive
than the other types of towers.
 More often than not they require
additional material to "Stealth"
their appearance and typically
don't provide the same amount of
capacity for tenants.

14. Cont…
Based on Installation Types
•Ground Base Tower: most of telecom towers are of 40 meters in Height.
•Roof top Tower: Range 9 meter to 30 meter
Based on applicability & antenna load
• Steel lattice structure : up to 300 feet
• Monopole: up to 199 feet
• Concealed : up to 150 feet
1 feet = 0.30480 meter & 1 meter = 3 feet

15. DEFINITION OF TOWER
 A cell tower is a cellular telephone site where antennae and electronic
communications equipment are placed, usually on a radio mast, tower
or other high place, to create a cell (or adjacent cells) in a cellular
network.
 The elevated structure typically supports antennae, and one or more
sets of transmitter/receivers transreceiver, digital signal processor,
control electronics, a GPS receiver for timing (for CDMA 2000/IS-95
or GSM systems), primary and backup electrical power sources, and
sheltering.

16. Cont…
 The working range of a cell tower or cell site (the range which
mobile devices connects reliably to the cell site) is not a fixed
figure.
 It depends on a number of factors:
 Height of antenna over surrounding terrain (Line-of-sight
propagation).
 The frequency of signal in use.
 Timing limitations in some technologies (e.g., GSM is
limited to 35 km, with 70 km being possible with special
equipment)
 The transmitter's rated power.

17. Cont…
 The required uplink/downlink data rate of the
subscriber's device.
 The directional characteristics of the site antenna array.
 Reflection and absorption of radio energy by buildings or
vegetation.
 It may also be limited by local geographical or regulatory
factors and weather conditions.

18. TELECOM TOWER COMPANIES IN THE
WORLD
With a portfolio of more than 1,14,101 towers, Indus is the largest
telecom tower company in the world.

19. IN INDIA
ATC India owns or operates over 12,000 tower sites throughout
the country.
Aircel
American Tower Co India Ltd
Bharti Infratel
BSNL Telecom Tower Infrastructure
Essar Telecom (ETIPL)
GTL Infrastructure
HFCL Connect Infrastructure – Infotel Group
Idea Telecom Infrastructure
India Telecom Infra Ltd
Indus Towers Ltd
Quippo Telecom Infrastructure Ltd [Viom Networks Ltd]
Reliance Infratel
Tower Vision India Pvt. Ltd
Vodafone

20. Cont…

21. ROLES & RESPONSIBILITIES OF SITE TECHNICIAN
Tower Site Maintenance
Regular Visit to site:
• Proper readings for EB, PIU…
• Check for lube oil, diesel level, water or coolant level in DG.
• Distilled water in the battery.
• Check the alarms on PIU.
Site visit in case of critical fault alert:
• Mains failure
• DG failed to start or stop.
• DG low fuel level
• Rectifier failure
• Power interface unit related
• All sensors
• Site Down
• High Temperature.

22. COMPONENTES OF TOWER SITE
Tower:
Platform
Mounting pole
Antenna (GSM, CDMA & Microwave)
Lightening Arrestor
Aviation Lamp
RF Feeder cable
Vertical cable tray
Earthing
Shelter:
BTS
Communication equipment rack
SMPS
Battery bank
Air Conditioning & fan unit
Sensors

23. Cont…
Fiber connectivity box
Router/modem
Smoke detector
Anti static floor mat
Fire extinguisher etc
Diesel Generator (DG):
PIU
Power cables
Three phase & single phase system
Cut out with handle
Circuit breaker
Transformer
Auto phase selector
AC & DC panel with different meter
AMF & interlock panel
Static line conditioner (LCU)
DG battery charger

24. Antenna
An antenna (or aerial) is an electrical device which
converts electric power into radio waves, and vice
versa.
It is usually used with a radio transmitter or radio
receiver.
An antenna consists of an arrangement of
metallic conductors, electrically connect to the
receiver or transmitter.
The first antennas were built in 1888 by German
physicist Heinrich Hertz.

25. Cont…
 According to their applications and technology available,
antennas generally fall in one of two categories:
 Omni directional antenna
 Directional antenna

26. CELLULAR NETWORK
A cellular network or mobile network is a wireless
network distributed over land areas called cells,
each served by at least one fixed-
location transceiver, known as a cell site or base
station.
In a cellular network, each cell uses a different
set of frequencies from neighbouring cells, to
avoid interference and provide guaranteed
bandwidth within each cell.

27. FEATURES OF CELLULAR NETWORK
More capacity than a single large transmitter,
since the same frequency can be used for
multiple links as long as they are in different cells
Mobile devices use less power than with a single
transmitter or satellite since the cell towers are
closer
Larger coverage area than a single terrestrial
transmitter, since additional cell towers can be
added indefinitely and are not limited by the
horizon

28. ANTENNA MOUNTING SYSTEMS
Tower Accessories -
T-Boom Sector Mounts
SAF-T Boom
Ice Shields
Antenna Mounting Kit
Pipe to Pipe Mounting Kit
Antenna Pipes....and more

29. Cont…
Pole Accessories –
 Tri-Collar Assemblies
 Monopole Platform Kits
 SAF-T-Arm
 Chain Mounts
 Access Ports and more..

30. Cont…
Rooftop mounts and Accessories -
Water Tank Mounts
Tri-pod Mounts
Ballast Frames
Rooftop Bridge
Equipment Racks
BTS Platforms and more..
Transmission line support system-
Waveguide Bridge
Trapeze Kits
Pipe Post Kit
Ladder Hardware Kit

31. Cont…
Cable hardware and accessories –
Feeder cable
Guy Cable Hardware Kits
Bird-Flight Diverter
Galvanized Hardware
Jaw-Eye Turnbuckle
J-Bolt & U-Bolt Assembly

32. DIFFERENT CELL STRUCTURES
Hexagonal
Circular
Square
Triangular

33. FREQUENCY REUSE
The key characteristic of a cellular network is the
ability to re-use frequencies to increase both
coverage and capacity.
The adjacent cells must use different
frequencies, however there is no problem with
two cells sufficiently far apart operating on the
same frequency. The elements that determine
frequency reuse are the reuse distance and the
reuse factor.

34. Why hexagonal cells are used ?
Avoid the gape between the cells.
Avoid the overlap between the cells.
Cell can be easily splitting and sectoring.
More capacity in the cell.
Just look likes circular in structure.

35. Cont…

36. ADVANTAGES OF HEXAGONAL CELL
There is no overlap between adjacent cells
No gap between adjacent cells
One of their features is the efficient utilization of
spectrum resources due to frequency reuse.
In practice, frequency reuse is a defining
characteristic of cellular systems.
It exploits the fact that signal power falls of with
distance to reuse the same frequency spectrum
at spatially separated locations (cells).

37. DISADVANTAGE
One disadvantage of a hexagonal cell is that hexes have
adjacent cells in only six directions instead of eight, as in a
square cell.
Commonly, cells will form continuous straight lines "up" and
"down", or "north" and "south", in which case the other four
adjacent cells lie "north-west", "north-east", "south-west" and
"south-east".
As a result, no hex cell has an adjacent hex cell lying directly
"east" or "west", making movement in a straight line east or
west somewhat more complicated than on a square cell.
Instead, paths in these directions, and any other path that does
not bisect one of the six cell edges, will "zig-zag"; since no two
directions are orthogonal, it is impossible to move forward in
one direction without moving backwards slightly in the other.

38. CELL SPLITTING
Cell splitting is the process of subdividing a congested cell into
smaller cells each with its own base station and a
corresponding reduction in antenna height and transmitter
power.
Cell splitting is done by defining and installing new cells which
have a smaller radius than the original cells (microcells) the
radius, R of every cell was cut in half, (R/2).
Cell splitting increases the capacity of a cellular system since
it increases the number of times that channels are reused.
The consequence of the cell splitting is that the frequency
assignment has to be done again, which affects the neighboring
cells.

39. CELL SECTORING
In this method, a cell has the same coverage space but instead of
using a single Omni‐directional antenna that transmits in all
directions, either 3 or 6 directional antennas are used such that each
of these antennas provides coverage to a sector of the hexagon.
When 3 directional antennas are used, 120° sectoring is achieved ,
and when 6 directional antennas are used, 60° sectoring is achieved .
Dividing the cells into sectors actually reduces the network capacity
because the channels allocated to a cell are now divided among the
different sectors .
Handoff takes place when a cell phone moves from one sector to
another in the same cell. The gain in network capacity is achieved by
reducing the number of interfering co‐channel cells.
If sectoring is done in a way that channels assigned to a particular
sector are always at the same direction in the different cells each
sector causes interference to the cells that are in its transmission
angle only.

40. CELL SPLITTING & SECTORING

41. MULTIPLE ACCESS TECHNIQUE
In case of mobile communication, which is a form of wireless communication, the
only restraint on communication is the bandwidth restraint which means we have a
limited frequency range that we can use for communication. Hence, we must
somehow, allow multiple users communicate in the same frequency range.
Multiple Access Techniques are ways to access a single channel by multiple users.
They provide multiple access to the channel. A “channel” refers to a system resource
allocated to a given mobile user enabling the user to establish communication with
the network (other users). Based on the type of channel, we can use a particular
multiple access technique for communication.
Frequency Channels [FDMA - Frequency Division Multiple Access] - Frequency
band divided into small frequency channels and different channels are allocated to
different users – like in FM radio. Multiple users can transmit at the same time but
on different frequency channels.
Time-slot Within Frequency Bands [TDMA - Time Division Multiple Access] –
Each user is allowed to transmit only in specified time-slots with a common
frequency band. Multiple users can transmit at the same frequency band at different
times.
Distinct Codes [CDMA - Code Division Multiple Access] – Users may transmit at
the same time using the same frequency band but using different codes so that we
can decode to identify a particular user.

42. FDMA
In FDMA, each user is allocated a unique frequency band or channel.
During the period of the call, no other user can share the same
frequency band.
Total frequency is divided in frequency slots.
It is a analog system.

43. FEATURES
Continuous transmission:- the channels are used on a non-time-
sharing basis.
Narrow band width:- Digital FDMA can make use of low bit rate
speech coding techniques to reduce the channel band even more.
Low overhead:- carry overhead messages for control
synchronization purposes.

44. TDMA
TDMA systems divide the channel time into frames. Each
frame is further partitioned into time slots. In each slot only
one user is allowed to either transmit or receive.
Unlike FDMA, only digital data and digital modulation must
be used.
Each user occupies a cyclically repeating time slot, so a
channel may be thought of as a particular
time slot of every frame, where
N time slots comprise a frame.

45. Features
Multiple channels per carrier or RF channels.
Synchronization needed.
Burst transmission since channels are used on a timesharing
basis. Transmitter can be turned off during idle periods.
Narrow or wide bandwidth – depends on factors such as
modulation scheme, number of voice channels per carrier
channel.
High ISI – Higher transmission symbol rate, hence resulting in
high ISI. Adaptive equalizer required.

46. CDMA
In CDMA, the narrowband message signal is multiplied by a very
large bandwidth signal called spreading signal (code) before
modulation and transmission over the air. This is called spreading.
CDMA is also called DSSS(Direct sequence spread spectrum).
FEATURES:-
No frequency management
No guard time required
Enables soft handoff

47. CDMA example

48. Cont…

49. SPREAD SPECTRUM
Spread spectrum is a communication technique that spreads a
narrow band communication signal over a wide range of frequencies
for transmission and de-spreads it into the original data bandwidth at
the receiver.
It uses wide band, noise like signals. Because spread spectrum
signals are noise-like ,they are hard to detect.
Spread spectrum signals are also hard to intercept or demodulate.
Further, spread spectrum signals are harder to jam(interfere with)
than narrowband signals.
These low probability of intercept(LPI) and anti jam(AJ) features are
why the military has used spread spectrum for so many years.

50. GENERATION (G)
0G refers pre-cellular mobile telephony technology in
1970s.
Technology used in 0G are PTT(push to talk),
MTS(mobile telephone system) & Improve-MTS.

51. 1G TECHNOLOGY
Developed in1980 in Europe.
Based on analog
telecommunication standards.
Used analog radio signals.
It allows voice calls in one country.
Technology: AMPS, CT series
Range:2.9 kbps to 5.6 kbps.

52. 2G TECHNOLOGY
Developed in 1990-91 in Finland.
Based on GSM technology.
Technology: GSM, CDMA, DECT…
Used digital radio signals and
SIM card.
Range: 15Kbps to 40Kbps.
GSM Services:
Tele-services
Supplementary services
Bearer services

53. 2.5G TECHNOLOGY
General packet ratio services(GPRS)
Data rates-56kbps to115kbps
Services-
 WAP
 MMS and SMS
 Search and directory

54. 3G TECHNOLOGY
Based on Universal mobile telecommunication
system(UMTS).
It is known as any where, any place, any time technique.
 Standards are: WiMAX, WCDMA 2000, WCDMA one,
CDMA 2000, HSPA etc
Range: (up to 2 Mbps)
144kbps to 384kbps in rural
384kbps to 27Mbps in urban
 First MTNL lunched in INDIA.

55. 3.5G TECHNOLOGY
HSDPA(high speed downlink packet access) is
referred in 3.5G.
HSPA+
Speed is up to 480kbps.

56. 4G TECHNOLOGY
Latest and fastest generation of mobile phone
communication.
It is known as MAGIC system.
Based on 3G technology with improvements named as
LTE.
MIMO, OFDM technique used.
First used in 2009 in Sweden
First Airtel lunched in INDIA, in 2012.
Data rate: up to 20Mbps-1Gbps

57. 5G TECHNOLOGY
Started in 2010.
Complete wireless communication
with almost no limitations.
It is highly supportable to
wwww(wireless world wide web).
Data rates more than 1Gbps.
Technology: Advanced LTE, mimo-ofdm

58. COMPARISON OF 1G, 2G, 3G, 4G, 5G