Column: Making scarce spectrum deliver more

Updated: Feb 16 2013, 07:37am hrs
To increase the information-carrying capacity of a channel, its bandwidth increase is the only solution

Pradip Baijal & Satya N Gupta

We know that as long as current management practices continue, radio spectrum will remain a scarce resource. Regulators and governments the world over are struggling to counter the crunch for decades to meet the ever-increasing demand from the operators, who are trying to meet the ever-increasing aspiration for high bandwidth consuming applications on their mobiles.

In reality, radio spectrum is not really scarce. Studies and reports to the governments by expert bodies in the US, the UK and the European Union have shown that the finite spectrum is currently highly mismanaged and grossly underutilised. To increase the information-carrying capacity of a channel, its bandwidth increase is the only solution. This can be achieved by avoiding fragmentation of spectrum, and techniques are now available to avoid fragmentation, even in a multi-operator multi-usage environment.

As an analogy, spectrum can be equated to real estate, which may be finite, but through multi-storied sky scrapers, the capacity of a build-up area on the same land can really be enormous. Real estate is also constrained by regulation (floor space index) and the technology and construction material used.

As far as options to enhance capacity are concerned, a niche role is required to be played by each key stakeholdergovernment, regulators, operators and network providers. The option available with the operators is to make use of frequency re-use techniques as a trade-off between the spectrum required and the number of towers to serve a particular subscriber base/data carrying requirement. This option is hardly exploited due to obvious high capex implications. On the part of the vendors, they are required to embrace the next generation technologies based on packet switching in access network also, which is very efficient. Of course, more and more work is already happening in this direction and vendors and R&D persons are not resting. The main discussion in this article is for the spectrum manager to learn from innovations in the management of finite resources.

The role of spectrum managers, either the government or the regulator, in increasing the efficiency of radio spectrum is of paramount importance as, being the custodian of spectrum, they are the first and most significant stakeholders in this value chain. To meet the objective, they need to innovate in management of spectrum and learn from the various advancements in this field. Many reports on these techniques are available the world over. One case in point is the emergence of packetisation techniques to improve the utilisation of a resource or media. This has been exploited fully by the internet and is now moving to telecom through next generation networks (NGN). Also, each stakeholder has to learn trunking techniques, wherein the same resource is shared among multiple users in a time-domain.

In addition, many regulators and operators have made use of time-slot interchange and packet-switching techniques to improve utilisation many-fold. Examples are internet exchanges, which help in efficient utilisation of precious international connectivity, interconnect-exchanges or telecom-hotels for efficient interconnection among multiple operators and, lately, the power-exchanges to help in the distribution of pooled power to the neediest entity at a given time.

Therefore, there is a life-time opportunity knocking at the doors of spectrum managers to come out of the stigma of gross mismanagement of spectrum, leading to dropped calls and slow net connections, by bringing efficiency not only in the utilisation of spectrum but also in its allocation.

Unfortunately, charity has to begin at home, as the most inefficient usage of radio spectrum is prevalent in the strategic and state entities. Defence forces are still using spectrum through outdated technologies and also in a fraction of the geography in which they have been allocated spectrum. In the same way, state broadcasters are still embracing spectrum-guzzling analogue technologies, though there is a strong movement towards a digital dividend. Also, not many public sector utilities are known to be efficient users of spectrum.

In the developing nations, especially the US and those in Europe, there is a pragmatic political move towards authorised shared access and pooled spectrum, wherein taking cognisance of interference-tolerant technological developments, the government is discussing the possibility of sharing strategic spectrum with the public operators, with a condition of first-right and zero-interference to defence usage. This is likely to work in 95% of the geography where defence forces have exclusive allocations but no operations. For the rest, public users will be allowed to use only if and when the spectrum is idling and without any interference to the original allottee, i.e. the defence forces. This appears to be a good beginning, but not enough.

The innovative, forward-looking approach for efficient spectrum allocation has to take the best of learnings from past, present and some out-of-the-box thinking to make it happen. One solution in this direction can be the establishment of a dynamic spectrum exchange for dynamically allocating the spectrum chunks from public switched spectrum pool (PSSP) to the neediest ones and temporarily withdrawing from the allottee who is not using it at the moment. This will work as a spectrum highway or a clearing-house, wherein a spectrum usage charge (SUC) will be paid based on the usage and not upfront. This process will also save the spectrum-hungry operators from the winners curse as they will pay-as-you-eat.

To take it forward, the government needs to set up an expert group of top brains in the country from all relevant segments and come out with a white paper and action plan. Then, a proof-of-concept project needs to be created to test, with about 100 MHz spectrum, wherever idling (like digital dividend band) or some strategic spectrum at a non-strategic location far away from security forces activity centres. This can prove to be the nirvana for all our spectrum woes and misdoings and help the nation to emerge as a pioneer and a super-efficient spectrum power, and consequently a knowledge powerhouse. Everyone knows we have the capacity, only we have to give tools to the maximum numbers in our very intelligent populace.

Pradip Baijal is former chairman, Trai. Satya N Gupta is former principal advisor, Next Generation Network, Trai, and chief regulatory advisor, British Telecom