Bharti Airtel's dispute with Tejas Networks has intensified, with the telecom operator reiterating that the Tata Group-owned company's equipment deployed by state-run Bharat Sanchar Nigam Ltd (BSNL) is "sub-standard," rejecting the local equipment maker Tejas's defence as unfounded.

Also Read: Airtel Alleges BSNL 4G Gear Causing Network Interference in Rajasthan; Tejas Denies

The row began after Airtel, in a November 14 letter, sought immediate corrective action from Tejas over persistent interference allegedly caused by the vendor's radio equipment installed at BSNL sites in Rajasthan. Airtel maintains that the issue stems from technical non-conformance in Tejas's radios and filter design. According to the operator, the filter supplied by Tejas was built for the 864-894 MHz range, as per certain international norms, while India's 800 MHz band operates strictly within 869-889 MHz. This deviation, Airtel said, results in spillover that disrupts its 900 MHz uplink.

"The claim made by Tejas Networks is baseless. Towers have historically accommodated two or more sites of different operators without interference, so the problem isn't due to closeness of sites. The current problem is more a function of sub-standard equipment which doesn't conform to Indian spectrum allocation requirements," Airtel said in a statement to The Economic Times, according to a report dated November 26, 2026.

Also Read: Tejas Networks Rejects Airtel's Claims, Blames Tower Proximity for Interference: Report

Tejas Networks has rejected the allegation, saying its radios meet all out-of-band emission specifications. In its November 24 response, the company attributed the interference to Airtel's decision to deploy sites in very close proximity to BSNL's, without ensuring adequate coupling loss to minimise signal disruption.

"The interference from BSNL to Airtel arises not due to Tejas's radios not meeting out-of-band emission specifications but primarily because Airtel's sites are deployed very close to BSNL's, without adequately maximising coupling losses," Tejas wrote in the November 24 letter, according to reports.

Airtel, however, dismissed this explanation, noting that telecom towers have historically hosted multiple operators without interference issues. It asserted that the problem lies squarely with Tejas's equipment, adding that all global vendors supplying radios for India's 850 MHz band comply with domestic spectrum norms. This means the signal from the 850 MHz band gets turned off within a certain limit and thus doesn't interfere with the uplink of the 900 MHz band.

"But the radio equipment made by Tejas for the 850 MHz for India - being used by BSNL - radiates signals beyond those limits, thus interfering with Airtel's 900 MHz uplink. To resolve the matter, Tejas needs to use a filter to ensure the equipment radiates signals only up to the limit," an Airtel spokesperson said, according to the report.

Airtel has urged Tejas to install appropriate filters to restrict emissions and prevent interference with its network operations.

Also Read: BSNL Flags Weak Signals at Thousands of New 4G Towers, Seeks Fix from TCS and Tejas

Earlier, in a separate row, BSNL had also raised concerns over weak transmission signals at thousands of its newly deployed 4G towers -- an issue contributing to call drops and slower data speeds. TCS and Tejas, in response to queries, reportedly said that most of these issues have been resolved and that there is no impact on BSNL's key performance indicators (KPIs).