Wireless DAS Update

AGENDA

• Wireless Infrastructure• Distributed Antenna Systems• Backhaul Antenna Systems• Summary• Q&A

Tony Whaley, RCDD/NTS/WD/CWP, CTSRTKL Associates, Baltimore, Maryland

Wireless Infrastructure

Wireless Infrastructure consist of antenna systems and the infrastructure needed to support them.

During this session we will discuss the types of wireless infrastructures:• The Distributed Antenna System.• Backhaul Antenna Systems.These wireless infrastructures are vastly used today and are critical to the

deployment of wireless services.

Distributed Antenna Systems

Overview• Distributed Antenna Systems (DAS) are the deployment of various antenna

configurations used to extend the coverage of wireless or mobile signals inside and outside of structures where RF signals do not reach and traffic density is often very irregular.

• Most people think of a DAS as an indoor antenna systems and most of our focus will be on indoor DAS applications, we will review campus and wide area DAS applications in minor detail.

• The size of the systems typically varies from a small repeater or enhancer system covering 2 or 3 floors of a small office block to large-scale systems using a Base Transceiver Station (BTS) to cover many floors or areas of a building complex or campus environment.

Distributed Antenna Systems Con’t

The two technologies that Distributed Antenna Systems will support are;

• Data Networks such as 802.11 Networks, WiMax Networks, and Blue Tooth Networks.

•Telecommunications Networks such as PCS, GSM, GPRS, iDEN, UMTS (3G).

The following is a brief overview of these networks.

802.11• What is an 802.11?IEEE standard that specifies medium-access and physical-layer

specifications for 1Mbps and 2Mbps wireless connectivity between fixed, portable, and moving stations within a local area. – 802.11a transmits radio signals in the 5 GHz range at a bandwidth

of 54 Mbps . – 802.11 b transmits radio signals in the 2.4 GHz range at a

bandwidth of 11 Mbps. – 802.11 g transmits radio signals in the 2.4 GHz range at a

bandwidth of 54 Mbps. – 802.11n transmits radio signals in the 2.4 and 5 GHz range at a

bandwidth of 245 Mbps.– 802.11y transmits radio signals in the 3.7 GHz range at a

bandwidth of 54 Mbps.

WiMax

• What is WiMax?802.16 (WiMax) is a group of broadband wireless communications

standards for metropolitan area networks (MANS). The original 802.16 standard, published in December 2001, specified

fixed point-to-multipoint broadband wireless systems operating in the 10-66 GHz licensed spectrum.

An amendment, 802.16a, approved in January 2003, specified non-line-of-sight extensions in the 2-11 GHz spectrum, delivering up to 70 Mbps at distances up to 31 miles.

IEEE 802.15 (Bluetooth)

What is Bluetooth?• Bluetooth is the name for a short-range radio frequency (RF)

technology that operates at 2.4 GHz and is capable of transmitting voice and data.

• The effective range of Bluetooth devices is 32 feet (10 meters). Bluetooth transfers data at the rate of 1 Mbps, which is from three to eight times the average speed of parallel and serial ports, respectively.

• Specification created in 1999 jointly by Ericsson, IBM, Intel, Nokia, and Toshiba

IEEE 802.15 (Bluetooth)

• Named after 10th century Danish Viking King Harald “Bluetooth Blaatand

• This is a technology that enables wireless communication between Bluetooth-compatible devices. It is used for short-range connections between desktop and laptop computers, PDAs (like the Palm Pilot or Handspring Visor), digital cameras, scanners, cellular phones, and printers.

Telecommunications Networks

Mobile Wireless or “Cellular Networking” is a frequency re-use strategy used by all of the mobile telephone systems (and some PBX/LAN’s)

Below are some of the more common Mobile Wireless Networks being deployed today:

• 800Mhz Cellular• PCS• GSM• ESMR• UMTS(G4)DAS will support these systems in an indoor environment and Wireless

Backhaul Antenna Systems are used to support them in an outdoor environment.

CELLULAR SERVICE

In Building ServicesCampus Distribution

Cellular Back Haul

Distributed Antenna Systems

DAS Components

• Antennas• Antenna Mounting Components• Cabling Distribution• Active Distribution Equipment• Passive Distribution Equipment

Antennas

Purpose and characteristics of Antennas

• An Antenna is a device to transmit and/or receive electromagnetic waves. Electromagnetic waves are often referred to as radio waves.

• Most Antennas are resonant devices, which operate efficiently over a relatively narrow frequency band.

• An Antenna must be tuned (matched) to the same frequency band as the radio system to which it is connected otherwise reception and/or transmission will be impaired.

Antenna Types

Primary Antenna types in DAS configurations are:• Omni Directional

– Broadcasts in all directions• Examples are whip, helical and dipole

• Directional– Broadcast in a single direction

• Examples are Yagi, and parabolic• Leaky Coax

– Broadcasts along path of the coaxial cable • Coaxial cable with the closely spaced slots in the outer conductor

allowing signals to penetrate to the core

Antennae Types

Omni Directional– Broadcasts in all directions

• Examples are whip, helical and dipole

Antennae Types

Directional– Broadcast in a single direction

• Examples are Yagi, Panels, and parabolic antennas

Antennae Types

• Leaky Coax– Broadcasts along path of the coaxial cable

• Coaxial cable with the closely spaced slots in the outer conductor allowing signals to penetrate to the core

Main Antenna Systems

Overview• The main antenna system acts as the “DEMARC” for

the DAS. It consist of either a line-of-site or non line-of-site antenna configuration which are used to extend the coverage of wireless or mobile signals outside of structures

• The main antenna system will capture, regenerate and broadcast the service provider signal to the Headend of the DAS.

CELLULAR SERVICE

Main Antenna System Components

• Lighting Protection• Cabling• Cabling Distribution• Building or Tower Mounts• Antennas

In Building-DAS Infrastructure

In Building-Das Infrastructure is compose of three major components: • Antenna Systems.

– Omni Directional– Directional– Leaky Coax

• Active Distribution Equipment– Head End– Back End

• Passive Distribution Equipment.– Directional Couplers– Bias Tees– Hybrid Couplers– Power Splitters

Antenna Placement

In-building DAS design typically uses omni or directional antennas to provide RF coverage for indoor areas.

The directional antennas provide high gain and allow the designer to control the signal coverage area.

The omni antennas are used in the center of large areas to provide 360-degree coverage patterns.

Some parameters to consider when selecting the type of Antennae are:• Antenna placement• Operating distance and transmitter power• Desired qualities like e.g.: small size, good gain characteristics, omni-

directional or directional radiation pattern. (consider also aesthetics)

Active Distribution Equipment

Active Distribution Equipment• Active distribution equipment consists of the electronics associated with

DAS which require separate input power, usually 110 V AC or 220 V AC. This equipment commonly consists of:– Transceivers– Power Supply Units– Amplifiers

Note: These will be manufacturer specific

Head-End Equipment• The primary device is the common control unit. The common control unit

consists of several subsystems that have specialized functions within the Distributed Antennae System architecture.

• The subsystems typically will include inputs for the signals that will be retransmitted through the Distributed Antennae System, the amplifiers for signal balancing, the output links to the back end devices consisting of either for fiber optic or coaxial cables, and the power supplies for delivering power to the transmission equipment.

Active Distribution Equipment

Back-End Equipment• Back end equipment is typically consists of active components that

transmit and receive signals from the head end equipment and the Antennaes within the Distributed Antennae System. Back end equipment is most commonly of the same make and manufacturer of the Head end equipment, as open standards do not exist which will support integration of multiple manufactures.

Active Distribution Equipment

Back–End Equipment (Continued)

• Back end equipment is interconnected to head end equipment via a backbone cable consisting of fiber optic or coaxial cabling. Cabling types will be determined specific to each manufacturer of Distributed Antennae System equipment.

• Back end equipment is interconnected to the antennaes within the Distributed Antennae Systems via coaxial cabling or unshielded twisted pair (UTP) as in the case of traditional wireless access points (AP).

• Back end equipment typically has a set number of devices and /or antennas it will serve. Sizing requirements will vary per manufacturer and are unique to each system.

Passive distribution equipment does not require external power input. These components can be used in conjunction to an active DAS, or as a completely passive system:

Directional Couplers• A directional coupler is a linear device which couples part of the

transmission power by a known amount out through another port, often by using two transmission lines set close enough together such that energy passing through one is coupled to the other.

Bias Tees• Typically in combination with a Power Supply, Bias Tees can be

used for remote powering of RF repeaters, tower-mounted amplifiers, relays or other bi-directional amplifiers in a wide frequency band while not disrupting the RF or AC signal.

Passive Distribution Equipment

Hybrid Couplers• The Hybrid Couplers have been designed to meet the special needs of

the wireless market. They are most commonly used to combine two wireless bands to a single antenna feed or distribution cable.

Power Splitters• A power splitter is a passive device, which accepts an input signal and

delivers multiple output signals with specific phase and amplitude characteristics. The output signals theoretically possess the following characteristics:– Equal amplitude– 0° phase relationship between any two output signals– High isolation between each output signal– Unequal Splitters– Unlike capacitive couplers, the unequal splitters maintain DC

continuity both to the main and coupled ports.

Passive Distribution Equipment

Cable distribution, three types of cable are commonly recognized. • Single-mode fiber optic cable.

– Single-mode fiber optic cable is primarily used for outdoor applications, interconnecting remote transceivers, up to 5 Km, back to the BTS.

– Multi-mode fiber optic cable is primarily used for indoor applications, interconnecting remote transceivers, up to 500 m, back to the BTS.

• Unshielded Twisted Pair cable. – Used for connectivity of Wireless LAN Access Points to the Backend or

Network equipment.• Coaxial cable.

– Used for indoor and outdoor applications, interconnecting Antennas to remote transceivers or repeaters in smaller applications, back to the BTS. In the case of LCX “Leaky Coax” the cable plant is the bi-directional Antennae system.

Media Needs Indoors

Design Considerations

There are two potential problems with using a DAS to support mobile communications in buildings and spaces that commonly require coverage by the retransmission of RF signals:

• The availability and usability of RF signals in the intended coverage areas (coverage)

• The ability to support the demands of the system users and recipients (capacity)

Design Considerations

The implementation of a well-designed and configured DAS should address either or both of these areas.Design requirements begin with a needs analysis and follow with the evaluation process for determining the specific configuration of the DAS. This is conducted in a minimum of three phases: pre-installation (Needs Analysis/Site Survey), installation, acceptance, and implementation.

Campus and Wide Area-Antenna Systems

There may be antenna systems that need to provide outdoor coverage for Campuses, parks, or cities. Usually the service being extended it the clients LAN of a WIFI Hotspot.

These systems will need and antenna distribution system that will support coverage in these locations. The Campus and Wide Area-Das (Outdoor) environments.

The major components are the antennas themselves and the mounting systems that will be used. In a campus or wide area environment and combination of buildings and towers may be used to place the antenna systems for area coverage.

The active and passive distribution equipment remains the same. The antenna system extends the service coverage.

Outdoors-DAS Infrastructure

Outdoors-Das Infrastructure is compose of several components: • Antenna Systems.

– Omni Directional– Directional

• Towers and Mounts– Self Supporting– Monopoles– Guys– On buildings and other structures

• Cabling Systems.– Coax– Single-mode Fiber

• Amplifiers and Couplers– Directional Couplers– Bias Tees– Hybrid Couplers– Power Splitters

Antennae Placement

Outdoor DAS design typically uses omni or directional antennas to provide RF coverage.

The used of towers and building will needed to support the antenna systems.

Some parameters to consider when selecting the type of Antennae and mounting location are:•The size of the area needing coverage.•The environment of the area needing coverage (buildings, trees, etc.).•Operating distance and transmitter power•Desired qualities like e.g.: small size, good gain characteristics, omni-directional or directional radiation pattern.

Design Considerations

Design ConsiderationsDesign requirements begin with • Needs Analysis/Site Survey• Evaluation Process for determining the specific configuration

of Distributed Antennae Systems. This process is conducted in a minimum of three phases: Pre-

construction, construction, and acceptance/implementation.

Back Haul Antenna Systems

Overview• Back Haul Antenna Systems are the deployment of

various line-of-site and non line-of-site antenna configurations which are used to extend the coverage of wireless or mobile signals outside of structures

• These systems provide point to point and point to multipoint communications over long distances in support of Cellular, PCS, SMR, Commercial Carriers, Unlicensed, and Licensed Wireless.

• The size of the systems typically varies with the type of system being deployed.

CELLULAR SERVICE

A Cellular Telephone System

Local OfficeLand-BasedSubscriber

Toll Office

Local Office

Bell OperatingCompany

SeparateSubsidiary

MobileTelecommunications

Switching Office

A

A

Legend:Trunks to Radios (not shown to all cell sites)

Control Paths

To Other Offices(toll and local)

System Components

• Radios and Radio Repeaters• Amplifiers and Filters• Cabling• Cabling Distribution• Towers and Mounts• Antennas

Tower Types–Self Supporting–Monopoles–Guys

Building Mounts–On buildings or other structures

Antennae Placement

Backhaul antenna design typically uses omni or directional antennas to provide RF coverage for point-to point and point-to-multipoint systems.

The directional antennas provide high gain and allow the designer to control the signal coverage area.

The omni antennas are used in the center of large areas to provide 360-degree coverage patterns.

Some parameters to consider when selecting the type of Antennae are:– Distance between points– Transmitter power– Antenna Gain– Mounting Requirements

Wireless Issues

• Speed• Reliability• Time to deploy• Re-use of investment• Hard to wire areas• License vs. un-licensed

• Interference• Security• Redundancy• Right of way• Permits & Zoning• Mobility• Cost

Network Topologies• Point-to-Point

–Single node to single node connection–Well suited for long distances, backhauls and dedicated

service extension and where narrow beam antennas are used

• Point-to-Multipoint–Allows multiple facilities to share a connection back to a

common source node–Highly flexible with minimal or no changes required to

install connections to additional facilities–Range is more limited due to a wider distributed power

area• Mesh (also referred to peer-to-peer or multipoint-to-multipoint)

–Highly flexible and provides for easy network expansion–Provides self-healing architecture–Reduces implementation and operating cost–Facilitates mobile operations

Topologies

Point-to-Point

Topologies

Point-to-Multipoint

Topologies

Mesh

Design Considerations

Design requirements begin with • Needs Analysis/Site Survey• Evaluation Process for determining the specific configuration

of Distributed Antennae Systems. This process is conducted in a minimum of three phases: Pre-

construction, construction, and acceptance/implementation.

Wireless Outside Survey

In performing an RF survey in a outside environment we will focus on the following area:• Site Location• Location Type (Building or Tower)• Location Infrastructure• Path Analysis• Survey Documentation

Onsite Survey Tools• GPS for recording actual coordinates

• Range finder for determining obstruction height

• Balloon Float for obtaining LOS

• Tape Measure

• 802.11B Card and Laptop for Live Survey

• Spectrum Analyzer

• Lighting Beacons, Flares and Spotlights

Summary

Wireless Infrastructure is critical in the support of our everyday needs.

The Distributed Antenna system enables efficient use of available frequency spectrum and allows for effortless frequency planning. Furthermore, the total cost of ownership is relatively inexpensive. A well design system should be easily expandable to encompass additional operators or frequency bands or provide additional coverage.

The Backhaul Antenna systems supports data, voice and video services in may environments and across vast distances.

Wireless DAS Update

Thank You

Tony Whaley, RCDD/NTS/WD/CWP, CTS RTKL Associates, Baltimore, Maryland

twhaley@rtkl.com