Lotus Tower: A way forward for Broadcasting

by Shanthilal Nanayakkara
Retired Principal Engineer, Digital Transition Division,
Australian Communications and Media Authority, Canberra

The tallest multi-purpose tower in Sri Lanka, the Lotus Tower, is scheduled to be re-opened in September 2022, sans broadcasting facilities. In 2011, the then government of the day promoted and proposed a multi-purpose tower which was expected to provide facilities for broadcasting, telecommunications/defence activities. It’s dual purpose was also to showcase the local attractions from the tower top, with multi-faceted public facilities sprinkled on the ground. Indeed, the intention was a good one, particularly in view of the imminent arrival of digital technologies in broadcasting. Moreover, it was high time that Colombo invested on a multi-purpose tower facility which had the potential to consolidate all broadcasting and telecommunication services, currently scattered on numerous towers around the city.

One of the primary aims, from a broadcasting point of view, was to encourage co-siting of all wide and medium coverage broadcasting services, both Radio and Television, onto one main facility. Many broadcasting services currently operate from independent locations in Colombo, some at their own sites. But the time has come for consolidation to aid efficient spectrum management and viewer/listener convenience, allowing domestic receive antennas to be oriented in one direction. More importantly, the consolidation of digital transmissions is a high priority to ensure the minimisation of variance of digital signals of all services at receive locations to prevent disparities in coverage, short falls and drop-outs.

The original proposal of the broadcast facilities was to accommodate both analogue and digital radio and television broadcasting transmissions serving the greater Colombo area. The then news release by the Telecommunication Regulatory Commission of Sri Lanka (TRCSL) indicated that the tower would be capable of accommodating 50 television and 35 FM radio services. This initial view of accommodating 85 broadcasting services in total is unlikely to materialise as discussed below in this article.

In September 2019, former President Maithripala Sirisena opened the Lotus Tower, sans broadcasting facilities. Now the Tower has other attractions but broadcasting and other communication facilities, which were intended to be the primary purpose of the tower, are absent.

Lotus Tower Broadcast Issues

It was my practice to conduct voluntary seminars to broadcasters and their staff, including Communications Engineers, on digitisation of broadcasting, during my visits to Sri Lanka over the years, so as to broaden their knowledge in these areas. Following one such seminar in 2015, I was asked about my views regarding a rumour that the broadcast antennas proposed for the tower were incompatible for wide coverage services. In order to assess the veracity of the rumour, I asked the questioner to provide me with information pertaining to the proposed designs. On receiving the design diagrams, I was aghast to see the incorrect and unsuitable nature of the proposed designs. After analysing the diagrams, I noted three major defects in the proposed designs;

Inadequacy of the proposed technical specifications to provide 35 FM and 50 Television broadcasting services covering Greater Colombo area;

The orientation of antenna plane was perpendicular to the ground instead of it being parallel to the ground (i.e. plane of polarisation of the antenna). I could not fathom how a contractor who may have had much exposure to such projects in their vast country and having possibly built many broadcast towers similar to the Lotus, could make such a simple error; and Absence of an Environmental Impact Study (EIS) on the potential impact of the cumulative electro-magnetic radiation levels on strategic locations close to the tower.

In order to facilitate wide coverage broadcasting signals, the antennas should be installed with their plane of polarization parallel to the ground but the proposed antenna diagrams for the Lotus Tower showed that the plane of polarization of the antennae were at right angles to the ground. This may help to serve a completely different purpose, thus reducing the broadcasting coverage capacity drastically. Around the same time, an Indian newspaper article had also questioned whether the Lotus Tower was to be used as a listening post to tap into signals from nearby countries.

I tried my best to reach out to politicians, including former President Maithripala Sirisena, to explain the problems confidentially and to provide solutions on a voluntary basis, given their sensitive nature. I went as far as getting appointments but was never given the opportunity to explain the situation directly. Another concerning fact was the absence of an EIS, even though there were key hospitals, hotels and luxury apartment complexes in the proximity.

In desperation, I approached the then High Commissioner for Sri Lanka in Canberra, Mr. S. Skandakumar who without any delay approached the Minister for Telecommunications in the Yahapalana Government, Hon Harin Fernando. The Minister promptly got in touch with me but soon afterwards explained it was within President Sirisena’s portfolio responsibilities. As it was something in which President Sirisena had previously not shown any interest, I published an article in the Island Newspaper as a last resort, highlighting the apparent defects carefully leaving out information of a sensitive nature. Member of Parliament Vasudeva Nanayakkara’s questioning of the project in Parliament in 2016 was based on this article (published on August 16. 2016).

My next attempt was to bring these issues to the attention of the contractor’s local team of consultants. I understood that the local consultants were all structural engineers with no broadcasting knowledge but when contacted, they tried vehemently to discourage me from pointing out the defects.

Sometime in 2019, I came to know that the Telecommunications Authority of Sri Lanka had sought advice from two International broadcast antenna companies about the veracity of my findings published in the article. Both Companies had confirmed that I was correct and one company later contacted me via LinkedIn to convey this. It was only due to this advice that the installation of the antennas and associated broadcast facilities were stopped in the nick of time. Had TRCSL and the local Consultants initially taken up my free offer of help, the Lotus Tower would by now be serving its purpose and earning millions of dollars.

Lotus Tower: Resolution of Issues

To ensure that the Lotus Tower now fulfills its primary purpose of providing a consolidated multi-user broadcast and communication facility, a considerable effort and capital would be needed as I understand that the initial contract has been concluded. This capital expenditure is estimated to be close to US $ 50 million for the provision of broadcasting facilities. This outlay could be recovered over a number of years from the sharing fees levied from the broadcasters, provided a pragmatic business plan is developed by a public private partnership (PPP). Such practices are currently used effectively overseas at multi-user broadcasting facility sites.

The process to be followed is broad and not confined to work on the tower alone. It is also quite probable that the initial proposal of 35 FM radio and 50 Television services may need to be considerably reduced due to numerous issues that have previously not been taken into consideration. These issues are briefly explained in the tasks ahead that are listed below. The possibility that the Lotus Tower facilities are not likely to be available to the originally anticipated number of radio and television broadcasters, may not necessarily be an issue as some broadcasters may opt out of consolidated services from the tower and continue to use their own facilities. However, the scattered nature of broadcasting services in Colombo, if not addressed, could consequently lead to interference between broadcasting services.

Tasks Ahead

The five vertical columns on top of the tower, where the antennas are planned to be installed, have physical weight carrying limitations due to top loading and the impact of wind. Therefore, there is a maximum antenna panel weight capacity that is permitted in each part of the five columns;Depending on the permissible total weight on each section of the five columns, the maximum transmission capacity of each antenna would need to be determined;

After identifying the intended broadcast coverage in the Colombo region, the maximum number of broadcast services permissible from each section of the columns would then need to be ascertained;

A close examination of the existing frequencies allocated to broadcasters who plan to share the facilities, is also required to avoid interference between services. This is a particularly significant task ;

An evaluation of the projected cumulative Electro-Magnetic Radiation (EMR) levels would need to be conducted and appropriate mitigating antenna design strategies employed. This would enable EMR levels at strategic locations such as nearby hospitals and residential and office complexes to be within the Internationally recognised EMR limits for public exposure; and An acceptable Business Plan should also be developed to ensure broadcasters are encouraged to use the Lotus Tower.