Community organisations and emergency response groups have criticised Telstra’s mobile coverage maps, arguing they may exaggerate the availability of reliable service in regional areas and could give travellers and emergency workers a misleading impression of network access.

The concerns come as Telstra disputes a proposal from the Australian Communications and Media Authority that would require telecommunications companies to adopt a new national standard for reporting mobile coverage. The proposal could significantly alter how networks present coverage areas, potentially removing a region roughly the size of New South Wales from Telstra’s current maps.

The regulator says the proposed system would make it easier for consumers to compare different mobile networks. It aims to introduce consistent labels such as Good, Moderate, Useable and No Coverage so that customers can better understand the level of service they may receive in a particular location.

Vodafone owner TPG Telecom previously claimed Telstra’s maps overstated its coverage area by about one million square kilometres, suggesting this could encourage customers to pay more for services that may not perform reliably in practice.

The Australian Competition and Consumer Commission has supported the regulator’s plan, stating that current methods used by telecommunications companies to estimate coverage vary significantly. According to the ACCC, this lack of consistency can produce maps that are difficult to compare and may not accurately represent real-world performance.

Emergency services groups have also raised concerns. The Central Highlands Volunteer Ambulance Association in Tasmania said reliable information about mobile coverage is critical for public safety. The group believes existing maps can overstate the availability of dependable service, which may lead travellers or emergency personnel to assume they have coverage when they do not.

Telstra has opposed parts of the proposed standard and has argued that some competing operators are attempting to confuse customers by supporting the changes. One key point of disagreement is the signal strength threshold used to define usable service.

Under the proposed standard, the boundary between Useable coverage and No Coverage would be set at a signal strength weaker than minus 115 decibels per milliwatt. Telstra has argued that this level is too strict and is advocating for a lower threshold of minus 122 decibels per milliwatt, which it says could still provide a basic outdoor service.

However, the ambulance association warned that lowering the threshold could create risks if people assume they have coverage when in reality the signal may not support reliable communication.

Signal strength measured in decibels per milliwatt indicates how strongly a mobile device receives a signal from a tower. As the distance from the tower increases, the signal weakens. Other factors such as terrain, buildings and even how a phone is held can also affect reception.

The New South Wales government has also expressed reservations about introducing more flexible thresholds. It noted that the minus 115 decibels per milliwatt level is already relatively generous compared with international standards. The government said introducing variations could complicate the system and make comparisons between networks more difficult.

Regional communities have also questioned the accuracy of the maps. The Mt Tomah and Berambing Community Association in the Blue Mountains has lodged a complaint with the ACCC, claiming that Telstra’s published 4G and 5G coverage in the area does not reflect actual user experience.

Members of the association conducted their own field testing and reported that areas labelled as having adequate coverage often had no usable signal at all. They said the gap between computer modelling used to produce coverage maps and real-world performance can sometimes be substantial.

Agricultural groups have raised similar concerns. The National Farmers’ Federation said farmers frequently report that the service available on their properties does not match the coverage indicated on network maps. According to the organisation, the reliability of these maps is essential for both safety and business operations in regional areas.

Telstra has defended its modelling approach, saying coverage maps are based on extensive simulations and real-world testing. The company said that within the disputed coverage area, around 700,000 phone calls and 750,000 text messages are sent each day. It also reported about 57,000 emergency calls are made annually in those locations.

A Telstra spokesperson said no coverage map from any telecommunications provider can guarantee mobile service at a specific place or time because network performance depends on many factors. The company said it continues to refine its modelling and testing processes to improve the accuracy of its coverage information.