BTS Signal Extension over Fiber: Application Note

Challenge: To provide superb coverage for VIP customers inside buildings

In congested, densely populated urban areas, operators use repeaters to provide better coverage to

customers. The downside of these Off-Air Repeaters is a lot of network interference during normal

usage. Users suffer from unreliable indoor cellular coverage, such as:

Poor calling quality

Call interference in the top floors of high-rise buildings

Poor reception in basements and underground parking areas

Slow Internet service (Throughput ─ MBps)

Dropped and missed calls

Intermittent lack of service

As competition increases, operators must deliver better coverage, while meeting increasing capacity

demands. Moreover, the need for improved bandwidth quality with minimal interference is crucial to

providing fast Internet connection and high throughput.

The Operators’ goal is to retain and increase their customer base, while decreasing costs on coverage

solutions, equipment and real-estate inside buildings. The use of repeater solutions results in a waste

of network resources.

Introducing Foxcom’s BTS Xtend Solution

Foxcom’s BTS Xtend solution, which is based on Foxcom’s In-Building wireless technology, specifically addresses coverage needs for important VIP users on targeted floors or blocks of floors.

Maintaining high quality service for preferred customers, results in a reduced customer churn rate to

the competition. In addition, the BTS Xtend solution uses minimum network resources.

In this configuration, a Base Transceiver Station Site (BTS site), which is centralized at one indoor or

outdoor location, serves multiple sites via pre-existing, underground fiber-optic infrastructure. Remote

Units (RUs) and antennas for a single operator are installed throughout locations, such as high-rise

buildings, basements and underground parking areas.

The BTS and each RU are connected by a single fiber. All cellular operator bands supported by this high

density solution are contained in one Remote Unit, including 2G (cellular, PCS/DCS), 3G (UMTS/AWS)

and 4G (LTE and LTE MIMO). The basic BTS Xtend system configuration consists of 4 cellular bands.

Confidential Information Foxcom BTS Xtend Application Note V1 2

BTS Xtend replaces the current repeater solution, which receives and transmits off-air signals that

cause a lot of interference.

DAS Capacity Comparison

Subject Repeater Xtend Solution

BTS DAS Passive Active

Site Coverage Performance

Poor in dense

areas. Repeater receives signal from multiple sites

Excellent Direct connection to BTS

Moderate Direct connection to BTS

Excellent Direct connection to BTS

Capacity Low (Limited) High (1 sector) High High

Coverage 1 room – a few floors

A few floors Full building Full building and massive venues

System Configuration

Repeater per technology (2G, 3G, 4G)

One system for multiple technologies, multiple services

One system for multiple technologies, multiple services

Equipment Costs

Low cost per band

Low─mid range Mid range High range

Impact on Cellular Network

Bad for UL

path resulting in high interference and use of network resources

No Impact No interference Direct connection to BTS; minimum network resources required (existing BTSs).

No Impact No interference Direct connection to BTS; BTSs added to cellular network.

Installation (Effort, Time, Cost)

Easy; Short installation

time; Low cost

Easy; Short installation time; Negligible cost Uses existing fiber optic cables between BTS site and each RU.

Moderate; Medium to Long installation time. Costly if not covering the entire building

A transmission line is required.

Service Port Output Power

0.01─ 10W per band

10W composite power per RU 10W─40W BTS output power to all DAS system antennas

10W composite power per RU

Foxcom’s active solution offers the most cost-effective, superb, high-capacity

coverage solution for targeted spots.

Confidential Information Foxcom BTS Xtend Application Note V1 3

System Architecture

Figure 1 shows the system architecture of the BTS Xtend product. From one BTS location via

underground fiber optic cables up to 8 RUs can be supported providing excellent service to users on the

top floors of high-rise buildings as well as basements of lower buildings.

Figure 1: BTS Xtend Architecture

* The four bands in this diagram are only an example. Different bands, including 4-band and MIMO LTE,

are also available.

RU

RU

RU

Underground

Fiber Optics

RU

RU

RU

RU

RU

Basement

Coverage High-Rise

Building

*

RU

Confidential Information Foxcom BTS Xtend Application Note V1 4

System Diagram

Figure 2: BTS Xtend Site Links to Two Locations

Advantages and Benefits

Real-estate savings

A single BTS located indoors or outdoors can connect to multiple RUs to provide coverage in multiple locations. Acquiring only one location for a BTS is highly cost-effective for a single cellular operator compared to acquiring a number of locations for multiple remote site locations. It is difficult to find available BTS sites in urban areas. In addition, the construction of an indoor BTS site (at each remote site) using traditional BTS installation methods and operating costs of multiple-BTS sites can be very expensive. BTS Xtend, which uses existing BTS real-estate and pre-existing underground fiber infrastructure, significantly saves on expenses.

Base Station savings

Today, each operator must provide services to end-users using multiple technologies, such as GSM900, UMTS900, GSM1800, LTE1800, UMTS2100 and LTE2600. Using the legacy method (without BTS Xtend), a BTS (or BTSs) supporting all technologies must be installed at each remote site. Each BTS requires a license and transmission connection, which costs a lot of money for the cellular operator, resulting in high operation costs.

Single Operator

Location B

Location A

Operator 1 Band 1

Compact Base

Unit

(CBU)

Remote

Unit (RU)

Operator 1 Band 2

Operator 1 Band 3

Operator 1 Band 4

Remote

Unit (RU)

Remote Unit

No. 1

Remote Unit

No. 2

Remote Unit

No. 3

BTS Site

Confidential Information Foxcom BTS Xtend Application Note V1 5

Using Foxcom’s Xtend solution requires only one BTS for up to 8 remote sites. The result is substantial savings of:

CAPEX: The initial cost of the BTSs as well as installation and commissioning of the BTSs at each remote site

OPEX: BTS license and transmission line payment

Scalability (Capacity / Traffic)

Foxcom’s system can be easily upgraded to support additional users (capacity) at a single location. Moreover, switching from mini-BTS to macro-BTS in the BTS site is relatively easy and low-cost when done at one location.

The scalability advantage is important to operators in the “customer acquisition” phase. However, even after the acquisition phase, the ability to balance traffic from location A to B to support increased capacity is very important.

Future proof

The cellular arena is changing all the time. New technologies appear faster than in any other arena. Therefore, the flexibility of concentrating cellular equipment, like BTSs and backhaul lines, in one location (BTS site) is a great advantage for upgrading.

Transmission line savings (local aggregation)

Foxcom’s solution only requires transmission lines in the BTS site. Saving transmission lines for all remote sites can result in substantial savings for the MNOs.

Aggregation of transmission lines in the BTS site can be utilized, resulting in additional savings on Operational Expenditures (OPEX).

For example: If 5 BTSs are installed in the BTS site, not all 5 lines are used 100% of the time. Therefore, an operator can use only 2 transmissions lines to aggregate the traffic from the 5 BTSs.

Reduced maintenance and operation costs

Maintenance and operation of each site costs money. By using compact equipment, such as Foxcom Xtend at each remote site, operation costs will be reduced dramatically.

Flexible site location

The distance between the BTS site and the Remote Site is calculated according to optical loss. The maximum optical loss supported by Foxcom’s system is 5dBo, which is equivalent to 15Km. This substantial distance affords great flexibility to the acquisitions department when selecting locations for remote sites and greater freedom to connect a lot of nearby locations to one BTS. Moreover, the compact size of the equipment makes site acquisition easier, resulting in better antenna location in urban areas. -----------------------------------------------------------------------------------------------------------------------------------

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All specifications are subject to change without notice. Rev 1 Mar 2014.