broadband deployment through tv-white spacetec.gov.in/pdf/studypaper/tvws_final.pdfmobile...

Broadband deployment through

TV-White Space Radio Division

Telecommunication Engineering Centre

Radio Division 1

1 Introduction

The 21st century has seen the dawn of the era of ICT (Information and Communication

Technology). ICT continues to shape societies and its contribution to global development

very much support every other input to economic growth and social development. Securing

access to efficient and sustainable ICT infrastructure has become a major goal worldwide,

especially considering the vital role that ICTs play across all areas of human life, such as

education, health, science, financial markets, security and civil protection, media,

entertainment and business development, amongst others. With the ongoing efforts to meet

this goal, there has been a steep increase in the demand for bandwidth for communication

systems and also the preferential shift from the usage of fixed wire-line technologies to

mobile technologies. With the drastic increase in the demand for mobile connectivity, comes

the inevitable pressure on the supply side of the resource, being the radio spectrum the

necessary resource to enable wireless technologies to transmit and receive data. It has been

felt worldwide to devise ways for efficiently managing the spectrum to serve the

exponentially growing demands. This has led to the development of different techniques for

addressing the spectrum crunch and also to optimize the use of the available spectrum.

One alternative mode of spectrum utilization that is finding popularity world over is the use

of TV White Spaces for communications systems. TV white spaces (TVWS) are “portions of

spectrum left unused by broadcasting, also referred to as interleaved spectrum”. The TV

White spaces have excellent propagation characteristics and hence are a huge attraction

worldwide for wireless communications. Countries like US, UK, Canada & Singapore have

already formulated regulations for the usage of TV White Spaces for wireless

communications ( fixed and mobile), and many others like Japan, Hong Kong etc. are

actively considering to do the same. This study paper briefly tries to cover the TV White

Space technology, the global scenario for the use of TVWS, the pertinent standards to the

TVWS system, the regulatory framework and other relevant points.

2 Definition of TV White Space

According to the CEPT (European Conference of Postal and Telecommunications

Administrations) Report 24, 2008 “Technical considerations regarding harmonisation options

for the Digital Dividend: A preliminary assessment of the feasibility of fitting new/future

applications/services into non-harmonised spectrum of the digital dividend (namely the so-

called "white spaces" between allotments)”:

‘White space’ is a label indicating a part of the spectrum, which is available for a

radiocommunication application (service, system) at a given time in a given geographical

area on a non-interfering / non-protected basis with regard to other services with a higher

priority on a national basis.


Radio Division 2

The TV White Space gets its name from the fact that it falls in the spectrum range of 470-890

MHz (ITU- Region 3 Frequency Allocations) which is the band allocated mainly for

Broadcasting as the primary service.

There are different ways in which TVWS can arise at any given location. The amount of

spectrum available in the form of TVWS can vary significantly across different locations and

will depend on various factors, including: geographical features, the level of interference

potential to the incumbent TV broadcasting service, TV coverage objectives and related

planning, and television channels utilization. The availability of TVWS can be mainly

categorized as; i) Frequency: idle channels of a TV band plan in some geographical areas

due to interference avoidance techniques like employing guard bands, ii) Height: defines the

availability of TVWS at a given area in terms of the height of the TVWS transmission site

and its antenna height, in relation to surrounding TV broadcasting coverage reception, iii)

Space: geographical areas that are outside the current TV coverage and therefore no broad-

casting signal is currently present. Also, those geographical separation areas (planned)

between locations using the same TV channels, iv)Time domain: a TVWS could become

available when a broadcasting emission is off-air; hence the licensed broadcasting transmitter

is not using the assigned frequency channel during a specific period of time and so making it

available for use as TVWS on non-interference basis.

3 Need for TVWS technology

Mentioned below are some of the key points that have led to the need for exploring

alternative and more efficient ways of spectrum utilization like TVWS:

Growing uptake of data-intensive applications and rapid consumer absorption of

novel mobile products.

Figure 1 Worldwide growth of mobile broadband


Radio Division 3

Figure 1 shows the rapidly growing mobile broadband usage in the world. In the

presence of band-width bottlenecks, potential regulatory choices for addressing such

issue would strive to achieve maximum spectrum efficiency through exploring forms

of dynamic spectrum access (i.e. cognitive radio, spectrum aggregation), sound

alternatives for spectrum sharing, and forward-looking spectrum planning and

refarming (and avoidance of spectrum fragmentation).

The low consumer base characteristics of rural and remote regions, along with

potentially more challenging geographical features, has contributed to the lack of

connectivity in such areas. Reaching these regions by means of fixed-line

infrastructure is capital-intensive. A wireless alternative is a more viable choice;

especially those alternatives than can achieve large coverage areas with fewer base

stations. This is where the TVWS technology comes into picture and can prove to be a

better choice for pervasive communication infrastructure in far flung and rural areas.

4 Technical overview of communication system employing TV White Space

A lot of studies have been carried out in European Union and ETSI and many countries have

also researched on the technologies to be used in the efficient deployment of TVWS

technology. In this section, some of the technologies related to TVWS have been briefly

described.

4.1 Cognitive Radio Technology

The TVWS technology based communication system is mainly based on the Cognitive radio

based architecture. ITU defines Cognitive radio system (CRS) as a radio system employing

technology that allows the system to obtain knowledge of its operational and geographical

environment, established policies and its internal state; to dynamically and autonomously

adjust its operational parameters and protocols according to its obtained knowledge in order

to achieve predefined objectives; and to learn from the results obtained. In the subsequent

sections, a brief description of a cognitive radio system is given.

Chief enabling technologies for the Cognitive Radio Systems are:-

Geolocation/Database

Spectrum Sensing

Combined Spectrum Sensing and Geolocation/Database

4.1.1 Geolocation/Database

In this approach, cognitive devices measure their location and consult a “geo-location”

database to determine which frequencies they can use at their location (location which they

have indicated to the database). Parameters such as location accuracy and frequency of

database enquiry are important. The devices are not allowed to transmit until they have

successfully determined from the database which channels, if any, are available in their

location. This requires that the initial access to the database is done either using a channel

reserved for this purpose or by some other means. Geolocation is an important part of the

database access approach as the location of the CRS node needs to be known to retrieve


Radio Division 4

correct information from the database for the specific location. There are several ways to

implement the geo-location. Fixed CRS devices such as access points can be professionally

installed and their location then programmed into the device. Personal computers and other

portable devices can use geo-location technologies such as GPS chips. Also triangulation

using radio towers or any other location determination method provided those methods

provide sufficient accuracy to determine the location of devices at a given point and time.

Once the device determines its location, or it is determined by the access point acting as a

master device, it can be communicated to the database to determine the frequencies

available for use in its area.

4.1.2 Spectrum Sensing

With spectrum sensing, devices try to detect the presence of protected services in each of

the potentially available channels. Spectrum sensing essentially involves conducting a

measurement within a candidate channel, to determine whether any protected service is

present. When a channel is determined to be vacant, sensing might be applied to adjacent

channels to determine what constraints there might be on transmission power, if any. A

significant advantage of spectrum sensing (stand alone) would be that it does not rely on

any existing local infrastructure, such as connection to a database or a beacon. This could

be important in remote and rural areas. However, if sensing thresholds are to be set very

low in order to protect existing services, this will result in increasing device cost and

complexity as well as a reduced number of available channels.

Currently different spectrum sensing methods are considered for CRSs.

These methods include energy detection, matched filtering, cyclostationary feature

detection and waveform based detection etc. These existing sensing methods differ in their

sensing capabilities, requirements for a priori information, and also their computational

complexities. The choice of a particular sensing method can be made depending on sensing

requirements, available resource such as power, computational resource and

application/signal to be sensed

4.1.3 Combined Spectrum sensing and Geolocation/Database

It is possible to use sensing in parallel with access to database. If this combined approach

were to be adopted then the following process may apply;

Identification of device location (information to be provided by the device to the

centralized database).

Identification of the usable frequencies and Effective Isotropic Radiated Power

(EIRP) (information to be provided by the database to the device).

Cross-check of availability of usable frequencies (spectrum sensing carried out by

the device).

Enable transmission (the device is transmitting). Transmission should be allowed

only upon confirmation by the geolocation database and by sensing.


Radio Division 5

The combined sensing and geolocation approach, where applicable, may have the advantage

of reducing the risk of interference compared to sensing or geolocation only.

4.2 TVWS Devices & Typical TVWS Architecture based on Geolocation Database

technique

The Geolocation Database technique for opportunistic spectrum access has been deemed as

the viable option for the TVWS technology based communication systems by industry and

administrations alike. The precision that is required for the spectrum sensing technique to

ensure operation on a non-interference basis is still to evolve into the device ecosystem.

Hence, from the point of view of deployment, the geolocation database technique is the

option in the current scenario. ETSI has published EN 301 598, White Space Devices,

Wireless Access Systems operating in 470-790 MHz band, in which the technical

requirements of a TV White Space device (TVWSD) is given in detail. The subsequent

sections give a brief description of TVWSDs as provided in the ETSI EN 301 598.

4.2.1 TVWS Devices (TVWSD)

As per the ETSI EN 301 598, TVWSD is a device controlled by a TVWSDB (TV White

Space Database) and which operates in TV white spaces. The ETSI EN defines two types

of TVWSDs, they are as described below:

Equipment Type A

A Type A TVWSD is a device that is intended for fixed use only. This type of equipment

can have integral, dedicated or external antennas.

Equipment Type B

A Type B TVWSD is a device that is not intended for fixed use and which has an integral

antenna or a dedicated antenna.

In addition to above, from operation point of view, the EN also lays down the following

category of devices:

Master TVWSD which has geo-location capability and communicates with a TVWS

Database for operation in the TV White Space.

Slave TVWSD which doesn’t have geo-location capability essentially and

communicates with the master TVWSD and other slave TVWSD while in operation.

The standard also defines a set of device parameters that the master and/or slave device

directly or indirectly (in case of slave device) communicates to the TVWS database for

operating in the TV White space. These parameters mainly include: Antenna location,

Antenna location uncertainty, Device type- Type A or Type B, Device category-Master or

slave, Unique device identifier, Technology identifier, Device Emission class, Spectral

mask improvement, Reverse intermodulation attenuation improvement etc.

4.2.2 TVWS Database (TVWSDB)

As per the ETSI EN 301 598, TVWSDB is the database system approved by the relevant

national regulatory authority which can communicate with TVWSDs and provide


Radio Division 6

information on TV white space availability. The TVWSDB formulates a set of Operational

Parameters like Lists of DTT (Digital Terrestrial Television) channel edge frequency pairs,

Maximum in-block RF EIRP, Maximum in-block RF EIRP for each DTT channel edge

frequency pair, Maximum nominal channel bandwidth, Maximum total bandwidth, Time

validity start, Time validity end, Location validity, Simultaneous channel operation power

restriction, Update timer etc. which it communicates to the master TVWSD (which

subsequently passes these parameters to its slave TVWSDs) before it can start operating in

the TVWS frequency and configure itself according to these parameters to avoid any kind

of interference to the primary service operators. The operational parameters also include a

set of Channel Usage Parameters that describes the radio resources the TVWSD intends to

use. The operational parameters are updated according to the geography of the environment

in which the TVWSD intends to operate and the TVWSDs are generally required to check

at least once in a day for these parameters so that they are aware of the current free

channels for operation in the TVWS, thus avoiding any interference to the incumbent

services.

4.2.3 Typical Architecture of TVWS technology

This section describes one of the implementations of operation of TVWSD and TVWSDB.

This implementation has been adopted by the Ofcom, UK for the deployment of TVWS

technology based networks in the country. Figure 2 depicts the architecture being followed

by Ofcom.

Figure 2 Typical implementation of Geolocation Database based TVWS technology

In a typical implementation, as shown in Figure 2 above, the TVWSD has to communicate

with a data repository to get the listing of the certified TVWSDBs. In this case, the TVWSD

uses a web-listing hosted on a server to get the information about the TVWSDBs and also

how to communicate with them. The TVWSDB stores information relating to the Terrestrial

frequencies in a geographical area, Information related to operation of Microphones in an


Radio Division 7

area, Interference Management Tools etc. In a typical implementation, these sets of

information/parameters can be managed in different databases which in turn can be linked to

a main TVWSDB.

Before radiating in the TVWS band, the TVWSDs communicate with the TVWSDB and

declare their location parameters to the TVWSDB, in accordance with which the TVWSDB

allots a certain set of operational parameters to the TVWSD for commencing operation. The

slave devices, as they cannot directly communicate with the TVWSDB, get their operational

parameters through the master device. A typical case of how the message flows between the

TVWSDB and the master/slave TVWSDs is depicted in Figure 3.

Figure 3 Typical representation of operational parameters exchange between TVWSDB and TVWSDs

4.3 Standards for Use of TV Band White Spaces

Many international Standards Development Organizations are working on creating a wide

variety of inter-operable standards and specifications for the use of TV Band white spaces.

Some of them are described below:

Institute of Electronics and Electrical Engineers (IEEE) 802 LAN MAN Standards

Committee is a leading consensus-based industry standards body, and it produces

standards for wireless networking devices, including wireless local area networks

(“WLANs”), wireless personal area networks (“WPANs”), wireless metropolitan area

networks (“Wireless MANs”), and wireless regional area networks (“WRANs”).

Included in the IEEE 802 standards development activity is an emphasis on

coexistence, which is the focus of the Wireless Coexistence working group.

Some of the IEEE 802 standards that are relevant to TV Broadcast Bands include

IEEE 802.11 AF (WLAN), IEEE 802.15.4m (WPAN), IEEE Std. 802.22-2011

(WRAN), and IEEE 802.19.1 (Coexistence). More information on these standards for

Television Band White Spaces and Spectrum Sharing can be found here33.


Radio Division 8

WhiteSpace Alliance has created inter-operability tests and certification procedures

for the IEEE 802.22 systems which is called Wi-FAR™. The Wi-Fi Alliance has

given the inter-operable IEEE 802.11 systems a commercial name of Wi-Fi®.

The Internet Engineering Task Force (IETF) Protocol to Access White Spaces

(PAWS) Working Group is working on creating a standard for interfaces and access

to the White Space Database by a White Space device operating in the Television

Broadcast Band.

WhiteSpace Alliance has also created inter-operability tests and certification

procedures for the IETF PAWS protocol which is called as the WSAConnect™

Specification.

5 TV White Space deployment scenarios

A number of deployment scenarios/use cases have been envisaged for communication

systems based on TVWS. The limit to the number of such use cases is only our imagination.

The industry has already done many pilot projects and proof of concepts to show case the

effectiveness of TVWS based communication systems in these deployment scenarios. The

standardization of different technologies pertaining to the TVWS is also being done keeping

in mind the specific deployment scenarios. The Main driver for the use of TVWS band is the

characteristics of radio waves in the UHF TV band, and their ability to penetrate deep inside

buildings. Some of these deployment scenarios include:

5.1 Rural Broadband

One of the significant deployment scenarios of TVWS based communication systems is the

rural or remote areas. These areas can benefit to a great extent by the deployment of TVWS

because of the sheer nature of the TV band waves having propagation characteristics to reach

tens of kilometers. These systems could be fast in deployment with minimal number of

repeaters.

Figure 4 depicts how a TVWS based communication network can be deployed in the rural

areas. Two main types of deployment options have been shown here. One depicts the master-

slave kind of communication between the WSDs, mainly a point to multipoint type of

deployment scenario. The slave WSD may then emulate Wi-Fi or any other communication

technology compatible with the User Equipment. If the user equipment supports, TVWS

communication standards like 802.11af then that can also be supported by the slave TVWSD.

The other scenario in the figure depicts the TV band being used to provide middle mile

connectivity to the Base stations and repeaters to reach the far flung rural areas which are

then served by Wi-Fi in the last mile. There can be other deployment scenarios pertinent to

the rural areas depending upon the requirement.


Radio Division 9

Figure 4 Typical implementation of rural broadband using TVWS technology

5.2 Hotspot coverage/In-building solutions for multimedia & broadband

TVWS owing to their inherent ability to penetrate deep inside buildings can serve as an

excellent candidate for providing Hotspot coverage and in-building solutions for broadband

applications. Since TVWSDs operate in the UHF band so they have a greater coverage as

compared to the devices in the ISM bands and hence an individual device in TVWS can serve

larger coverage area than the one in ISM band. Also, this to some limit curbs the interference

problem that is the biggest setback for Wi-Fi communication when a large number of Access

Points are collocated. Figure 5 below shows the typical deployment scenario for In-building

solutions in TVWS.

Figure 5 In-building solution with TVWS

5.3 Smart Grid Applications of TVWS

The spectrum crunch has led to many utility companies to look towards TVWS based

communications. One of the best examples of this being application of TVWS in Smart

Grids. Companies are using TVWS to provide middle mile connectivity to facilitate smart

metering and other smart grid solutions. As these applications are not very bandwidth


Radio Division 10

intensive, a limited number of TVWS channels are required for this kind of applications.

Singapore has deployed a number of TVWS based Smart Grid solutions in their country.

Figure 6 below depicts such an implementation.

Figure 6 TVWS in Smart Metering

5.4 TVWS in M2M communications

M2M communications is the future that we are pacing towards. M2M communication

consists of very low-power radio transmitters used for low-data rate industrial and

commercial applications such as monitoring, tracking, metering and control (a realization of

the concept of “smart machines”). The realization of smart cities is possible through the

complete manifestation of M2M communications. Recently, a proprietary open specification

for M2M devices, intended for operation in TVWS, has been agreed at a preliminary stage in

the United Kingdom under the umbrella of a Special Interest Group (SIG): Weightless SIG.

This group released in April 2013 a draft specification for low-data rates M2M devices

(hence the name “weightless”) to operate in the terrestrial television bands, transmitting data

over idle television frequency channels in geographical areas where TVWS can be found

(also querying a master frequency database). The Weightless M2M devices are intended for

operation on a license-exempt framework under a non-interference/non-protection basis. As

the use of M2M devices grow, and more applications connect to the “internet of things”, it is

expected that numbers of M2M devices deployed will grow exponentially, especially

considering the higher coverage ranges offered by the terrestrial television frequency bands.

6 Worldwide regulations pertaining to TV White Space

The TVWS technology has gained a lot of momentum in the global scenario with some

countries already devised regulations for TVWS usage and others are in the hoard to do so.

Countries like USA, UK & Singapore have already put a regulatory framework in place for

the operation of TVWS devices and have already carried out many pilots with the industry to

check their feasibility and effectiveness. All these countries have gone for license exempt

regime for the operation of TVWS and restricted the regulation to certification of the TVWS


Radio Division 11

databases and TVWS devices. This has been a welcome move from the authorities for the

industry and can act as a huge facilitator for pervasive communication infrastructure with the

use of TVWS. The countries have put some protection requirements that the TVWS operator

needs to adhere to so that the incumbent services are free from any kind of interference from

TVWS devices. In the subsequent sections, we discuss the TVWS framework in these

countries.

6.1 USA

The United States is the pioneer in developing the TVWS technology. In 2010, FCC adopted

a license-exempted regulatory framework for TVWS devices, with the management of

TVWS devices through on-line databases. FCC has granted approval to a number of

companies to operate their database systems to provide service to certified unlicensed devices

that operate in the TV band.

All TVWS devices require certification from FCC. The maximum equivalent isotropically

radiated power for fixed TVWS device is 4 W and that for portable TVWS device is 100

mW. Details of the technical parameters of TVWS devices can be found from Subpart H

(Television Band Devices) of Part 15 (Radio Frequency Devices) of Title 47 of the Code of

Federal Regulations (47 CFR).

The first commercial application of TVWS in the United States is a rural broadband service

which has been launched in April 2013 in the area of Northern California called El Dorado

County, or Gold Country. Cal.net, an ISP, is partnering with Carlson Wireless Technologies,

a network equipment provider, to bring wireless broadband service to the said area with the

speed of around 2 to 4 Mbps.

6.2 UK

The United Kingdom is active in conducting trials and consultations on TVWS where Ofcom

has been evaluating the applications of TVWS for a number of years. Some TVWS trials

have been conducted in Cambridge areas using database systems from Spectrum Bridge and

Microsoft.

Following a series of consultations, Ofcom issued a statement titled “Implementing

Geolocation: Summary of consultation responses and next steps” which set out the approach

to implement the geolocation method to allow licence-exempted wireless devices to access

TVWS spectrum in September 2011. The statement concluded that licence-exempted devices

could be authorised to use TVWS so long as they radiated in specific frequencies and at

specific powers in accordance with TVWS databases that met Ofcom’s requirements. Under

these conditions, it believed that such TVWS devices would not cause harmful interference to

the existing licensed services.

Ofcom has issued a consultation paper titled “TV white spaces: approach to coexistence” in

September 2013. This paper sets out the proposed framework of WS technology in the United

Kingdom. More specifically, the paper presents proposals for the parameters and algorithms

that will determine the available frequencies and powers (TVWS availability) for use by


Radio Division 12

TVWS devices in the TVWS framework. These proposals aim to ensure a low probability of

harmful interference to other services using the UHF TV band or adjacent bands.

Ofcom has been conducting a pilot which aims to test interactions between devices and

databases so as to provide an opportunity for the industry to conduct trials, and to gain further

information on the coexistence issues. A number of companies are taking part in the pilot,

either as databases, devices or service providers, providing input and expertise on coexistence

testing, offering trial locations, and volunteering as pilot users.

In February 2015, Ofcom in its statement titled ‘Implementing TV White Spaces’ conveyed

its decision to allow a new wireless technology access to the unused parts of the radio

spectrum in the 470 to 790 MHz frequency band. The statement elaborated that the new

technology, known as white spaces devices, will share this band with the existing uses,

Digital Terrestrial Television (DTT), including local TV, and Programme Making and

Special Events (PMSE), including in particular wireless microphone users. The statement

also defined the operational characteristics of the system which is based on Geolocation

database approach with measures to avoid any interference to the incumbent users of TV

band. Ofcom also communicated that its objective is to complete the implementation of our

decisions so the new technology can be deployed by the end of 2015.

6.3 Singapore

Since 2009, IDA of Singapore has conducted a number of TVWS trials to study the benefits

of the technology and concluded that TVWS can increase the availability of broadband

services and improve overall spectrum efficiency. Subsequently, an industry consortium

known as the Singapore White Space Pilot Group (“SWSPG”), with support from IDA,

launched a series of TVWS pilot projects in various parts of Singapore. These pilot projects

utilised a geolocation database which explore how WS technology can supplement and

enhance the existing broadband infrastructure, overcome challenging terrains, and enable

innovative consumer and business applications.

In June 2013, IDA issued a consultation paper on “Proposed Regulatory Framework for TV

White Space Operations in the VHF/UHF Bands” to seek the views of the industry on the

proposed license-exempted regulatory framework with a view to facilitating the deployment

of TVWS technology. In June 2014, the IDA issued a decision paper titled “Regulatory

framework for TV white space operations in the VHF/UHF bands”, which came into effect

on 1 November 2014.

Under Singapore’s framework, the operation of TVWS devices is on a license-exempted

basis, subject to certain technical specifications and prescribed operational parameters. In

addition, TVWS equipment is also subject to certification and registration. In order to prevent

interference, spectrum not used for supporting television broadcasting in Singapore is made

available for TVWS applications. IDA also makes clear that when analogue television is

eventually switched off and the 700 MHz band (i.e. commonly referred to 698 – 806 MHz

band) is ready to be allocated for International Mobile Telecommunications (“IMT”) services

in Singapore, the original channels in the 700 MHz band for use by TVWS devices will be


Radio Division 13

vacated for IMT services. All WS databases need to be licensed by IDA, but there is no limit

on the number of WS database providers.

7 TVWS in the Indian scenario

Before discussing TVWS technology in the Indian purview, it is imperative to examine the

frequency allocation in the UHF band in India as per NFAP 2011. The table below depicts

the frequency allocation in India in the UHF band.

To proceed further in examining the TVWS technology in the Indian scenario, following key

factors need to be considered:

Spectrum considerations

As it is clear from the table, that one of the key differences between the TVWS scenario in

the USA, UK and that in India is the frequency allocations in UHF band for India as per ITU

and NFAP 2011 for Region 3.The ITU allocates Fixed and Mobile Services as Primary

Services in the UHF band for Region 3 whereas these are Secondary Services as per ITU

allocation for Region 1 & 2 i.e. for USA & UK. So while considering the operation of TVWS

devices in this band, it should be kept in mind that the spectrum in this band can be

reallocated to IMT services too, much similar to the case of Singapore.

Also, as Doordarshan is the only terrestrial broadcaster in India, and once it completes the

digitization of its broadcasting services then it will be limited to a small region of the UHF

band and most part of the band will lie vacant. There has to be the assessment that whether

the use of TVWS technology be allowed only in the white spaces between the occupied

broadcasting channels or to the remaining part of the unused (which forms the major portion

of the UHF band) or freed spectrum after digitization.

Department of Broadcasting also needs to be consulted to gather data regarding the spectrum

usage for terrestrial broadcasting over the entire geography of the country so that their

services are protected if and when TVWS technology is deployed.


Radio Division 14

Technology considerations

As discussed before, the TVWS technology can be deployed using the Geolocation as well as

the Spectrum Sensing technique. US while making regulations for the technology had put

Spectrum Sensing as a mandatory requirement for TVWS deployment but due to the

equipment ecosystem not being at par with the regulation regime, they dropped the

requirement of Spectrum Sensing and finalized regulations based on the Geolocation

Database technique. The same has been followed by UK and Singapore as well. India may

also stick to the Geolocation database technique for TVWS deployment with the addition of

Spectrum Sensing as an optional feature which can be adopted when the equipment

ecosystem permits.

Also, in the case of India, since there is only one terrestrial broadcaster i.e. the Doordarshan,

it can be much simpler to implement the Geolocation database based TVWS communication

system because the TVWS providers have to co-ordinate with a single entity.

In the current Indian telecommunication scenario, rural broadband will be the priority use

case for the deployment of TVWS technology, but in the not so distant future, upcoming

technologies like M2M and Wi-Fi Hotspots in TVWS band will be deployed in a big way,

which will at the beginning be focused in the urban areas, it will be imperative to devise a

mechanism for the interference free co-existence of both the broadcasting and fixed/mobile

services with the TVWS services.

Licensing regime

The pertinent question is also whether India will go for a license exempt regime for TVWS

operation, and like other countries designate channels to be used by TVWS devices for

operation upon opportunistic and sharing basis. As there could be the case that a huge chunk

of the spectrum in UHF band will be available for services other than terrestrial broadcasting,

so it also needs to be assessed that whether most part of this spectrum be allocated for

licensed IMT services and TVWS will be restricted to the gaps in the digital broadcasting

band or some other arrangements will be made. Another crucial point for consideration is

that the UHF band is available for Fixed and Mobile Services as Primary Services in India, so

if in the future allocations for Fixed and Mobile services in this band for technologies other

than TVWS are done, then its impact on the TVWS operation also needs to be thoroughly

assessed. Interference studies need to be carried out for co-existence of TVWS with other

services other than broadcasting.

The regulators should also make sure that optimal spectrum utilization is achieved and

enforced even if license-exempt operation of TVWS technology is adopted. A thorough

framework to ensure this needs to be devised.

Also to be assessed is the framework that India will be following in maintaining the TVWS

database, whether the TVWS database will be managed by a third party or it will be state


Radio Division 15

owned with access to TVWS operators. Also if the authority will maintain a repository of and

certify TVWS devices, this needs to be decided. Due consultation with the stakeholders needs

to be carried out, as was done by all the countries who have framed the regulations for

implementing TVWS technology, for formulating the regulation regime for India.

Additional Considerations

As India is only beginning to warm up to the implementation of TVWS technology, there are

few crucial points (also underlined in GSR 13 ITU discussion paper on TV White Spaces)

from regulatory point of view that should be kept in mind for formulating the framework for

operation of TVWS technology, these are:

Carrying out studies necessary to assess the level of compatibility between license-

exempt TVWS devices and licensed mobile services, if further allocations are made

for the mobile service in the UHF TV band.

Assess the possibility to guarantee a continuity of service for TVWS service providers

in UHF TV spectrum bands in areas of the country where DTT deployment is still

ongoing.

Need to consider some form of assurance of availability of spectrum for a defined

period of time for TVWS service providers in order to provide them with a minimum

“spectrum pool” for successful service provision.

Studies necessary to assess the level of availability of TVWS in a combined

deployment scenario including TVWS Wireless Access Networks, wireless micro-

phones and TVWS M2M devices.

Impact on service provision due to bandwidth bottlenecks in cases of low TVWS

availability (depending on geography or otherwise)

Potential bandwidth bottlenecks for TVWS backhaul service providers.

Benefit to come to local mobile operators and small rural ISPs from opportunities

through TVWS. Types of services that are expected to be offered by TVWS service

providers after the pilot projects and the regulation upon them thereafter.

In terms of TVWS service provision and TVWS central database management, need

to review the legal framework and propose new regulatory arrangements or assess the

possibility of conflicts of interest between these two service areas.

Potential level of scalability, resiliency and reliability that TVWS service providers

can offer.


Radio Division 16

8 Conclusion

There is no denying the fact that TVWS is one of the best candidates to curb the spectrum

crunch that is being faced by the global communication scene. It not only offers better

spectrum management but due to the inherent propagation characteristics of the UHF band is

an economically viable solution. Not only developed nations are cashing on the advantages of

TVWS technology but countries with minimal communication infrastructure are going for it

because of its ease of deployment, being mainly in the license exempt regime, and serving

large coverage areas. The TVWS device ecosystem and other standardization initiatives are

coming up very fast and this technology is soon going to be a pervasive phenomenon in the

global telecommunication landscape.

As already elaborated in Section 6 of this study paper, USA, UK and Singapore already have

laid down necessary framework and regulations for TVWS deployments. USA already has a

number of certified database administrators and is the front runner in the deployment of

TVWS based networks. UK and Singapore are also hastening in the deployment process. UK

has had a number of pilot deployments pertaining to the use cases of Smart City, Rural

Broadband, Wi-Fi Hotspot coverage, M2M communications, sensor networks etc. Singapore

has deployed many smart grid solutions based on TVWS and is undertaking many pilot

deployments for a number of use case scenarios.

It cannot be enough emphasized that India can make good use of this technology to revitalize

its communication infrastructure. TVWS can act as one of the facilitators in making India

meet its long term goals of Digital India and Smart Cities. Rigorous consultation procedure

for assessment has to be adopted to hail the dawn of this technology in India. The pioneers of

this technology are already taking interest in the Indian market and India should reciprocate

their interest by coming up with a facilitating framework for this new technology, keeping in

mind the following main points while formulating the regulatory framework for the TVWS

technology

The spectrum allocation considerations for TVWS.

The TVWS database ownership and management considerations incorporating the

security considerations for access of such databases.

Certification of TVWS devices and databases.

Any licensing considerations.

Active involvement of DoT/TEC in pilot projects being undertaken for TVWS

technology deployment.

Other pertinent aspects as elaborated in Section 7.

REFERENCES 1. ETSI EN 301 598 White Space Devices (WSD); Wireless Access Systems operating in the 470 MHz to

790 MHz TV broadcast band; Harmonized EN covering the essential requirements of article 3.2 of the

R&TTE Directive

2. ITU GSR 2013 Discussion Paper

TV WHITE SPACES: MANAGING SPACES OR BETTER MANAGING INEFFICIENCIES?


Radio Division 17

3. Research Paper on White Space for Digital India

by CMAI Association of India in association with WhiteSpace Alliance, Indian Institute of Technology,

Bombay,Telecom Equipment Manufacturers Assn. of India

4. ECC report 159

Technical and operational requirements For the possible operation of cognitive radio systems

In the ‘white spaces’ of the frequency band 470-790 mhz, Cardiff, January 2011

5. Ofcom Statement on Implementing TV White Spaces, February 2015.

6. FCC SECOND MEMORANDUM OPINION AND ORDER on TV White Spaces

Adopted: September 23, 2010 Released: September 23, 2010

7. FCC THIRD MEMORANDUM OPINION AND ORDER on TV White Spaces

8. Decision Paper Issued By The INFO-COMMUNICATIONS DEVELOPMENT AUTHORITY OF

SINGAPORE ‘Regulatory Framework For TV White Space Operations In The VHF/UHF Bands’, 16

JUNE 2014

9. Telecommunications Regulatory Affairs Advisory Committee (TRAAC), Hong Kong Paper No. 6/2014

20 November 2014 on ‘Development of TV White Space Technology’.

broadband deployment through tv-white spacetec.gov.in/pdf/studypaper/tvws_final.pdfmobile...

Documents