Broadcasters cite 5G interference as guard band gets narrower

Broadcasters had earlier told the government that they would require a minimum guard band of 100 MHz from the 3600 MHz frequency band and start their services from 3700 MHz. “The 100 MHz guard band is absolutely crucial for the broadcasting industry. It gives us enough cushion to avoid any interference by telecom signals and ensures that our services keep running unhindered,” an executive from the broadcasting industry said, requesting anonymity.

Amitabh Kumar, Head of Technology & Broadcasting at Zee Network, said, “Satellites use the frequency of 3700-4200 for broadcasting. Before the 5G services began, the entire spectrum between 3600 Mhz and 3700 was left open as guard band.” But the recent 5G allocation, he added, stretches up to 3670 Mhz. Now, it has been left to the distribution platform operators (DPOs) to take care that they are sufficiently protected from the interferences from the 5G services as the mid-band transmissions are very close to the downlink frequencies, said Rajiv Khattar, former President of Projects at Dish TV. Currently, the telecom companies have been given frequencies in the range of 3630 Mhz, and shortly frequencies up to 3670 will be used for the 5G services. The downlink of the TV signals starts at 3700 Mhz, so the likelihood of interferences is high, Khattar added.

Bandpass filters are a critical device to mitigate the risk of interference. The Telecom Engineering Consultants, which is the technical wing of the Department of Telecom (DoT), has released the generic specifications of the bandpass filters that will help address possible interferences.

But presently, there is no indigenous manufacturer of bandpass filters and the demand will have to be fulfilled by imports. It will be well worth it if the government extends some financial incentives to DPOs from the spectrum auction earnings in the procurement of bandpass filters, else the broadcast stakeholders will have to make substantial investments in procuring bandpass filters, Khattar says.

Not having a 100 MHz guard band could disrupt the operations of a number of TV channels that operate below the 3800 MHz frequency band. According to the Indian Broadcasting and Digital Foundation (IBDF), an industry body of broadcasters and cable TV operators, there are close to 200 channels that operate in that frequency range. These include some channels owned by Sahara and some other news channels, among others.

There have already been a few instances of service disruptions at cable TV and broadcasters’ end due to interference from mobile telecommunication signals. In December 2021, an entity called Sai Vision cable network complained to the TRAI regarding interference to broadcasting signals in C-band from 5G trials. The complaint was later forwarded to the DoT which said that the entity started using 5G filters to mitigate the issue. A broadcasting industry executive said there were service disruptions experienced in some parts of West Bengal in September during 5G trials in the state.

The Telecom Regulatory Authority of India (TRAI), in its final recommendations before the spectrum auction, told DoT that broadcasters should make do with a 30 MHz guard band so that the frequency band between 3300 MHz to 3670 MHz could be utilised for mobile communication and 5G services by telecom operators. It also argued that broadcasters could use a cavity filter on their systems to coexist with telecom services in the mid frequency band range.

Globally, China has restricted mobile telecommunications in the 3300-3600 MHz band, according to a submission by the IBDF to the TRAI. In Australia, when the government allocated spectrum to 3700 MHz to telecom companies in 2018, “operators of TV and other C-Band services faced severe disruption post the allocation to 5G,” the IBDF said. South Korea, the IBDF said, is one of the countries which has auctioned spectrum till 3700 MHz, noting that the country does not use satellite C-Band extensively for cable and satellite services.

Broadcasters say that under the new National Frequency Allocation Plan (NFAP), the government has reduced the guard band between broadcasting and 5G services contrary to their own TEC guidelines and TRAI recommendations. On May 2, IBDF

had written a letter addressed to I&B Secretary Apurva Chandra, “reiterating their concerns regarding impinging on the use of C-Band spectrum, specifically 3.6-4.2 GHz”.

Citing TRAI recommendations on 5G Auctions which have been released on 11 April 2022, it said: “TRAI in its recommendations (which inter-alia contains recommendations for the auction of the 3300-3670 MHz band) has specifically outlined the actions on part of the MIB based on the realisation that the proposed auction of the 3300-3670 MHz bands will cause serious interference in C&S services.”

It said that the TRAI has accepted that “there will be interference in the bands of 3700-4200 MHz used by C&S industry; that there is need to use filters… to eliminate interference; and that MIB needs to sensitise MSOs, DTH Operators and other C&S users on this subject and implications.”

They said the C-band spectrum is the only spectrum allocated and being utilized by the broadcast industry today (between 3700 MHz – 4200 MHz) will be rendered incapacitated if the immediately adjoining frequencies between 3300MHz – 3670/ 3700 MHz are used for 5G.

“This has already played out in the UAE, Singapore, EU and the US where satellite reception has been adversely affected due to 5G roll out in the adjoining frequencies,” the letter said, “as a consequence, there will be huge disruption in the cable and satellite industry and thousands of cable operators and millions of consumers stand to be affected.”

Officials from I&B Ministry told the Indian Express, “The filters will surely be needed with the 5G rollout. It is incumbent upon the cable operators, MCOs and LCOs to acquire the filters and get them installed.” The ministry adds, “This may not be an immediate requirement but going forward, this will be required. Even Doordarshan will use the filters.”