Imagine you could see New Zealand’s mobile network as a landscape of invisible highways in the sky.
The backbone of this world isn’t the phone in your pocket - it’s the mobile sites (also called cell sites) scattered across our cities, towns and highways, connecting your phone to the mobile network.

A mobile site is more than just a physical structure. What really matters is the radio technology and spectrum each mobile network uses to deliver coverage - the equipment that keeps you connected to your whānau and friends wherever you are. At One NZ, this radio equipment is installed nationwide on thousands of structures, including rooftops, poles and on shared rural sites.

But here’s a key distinction that often gets missed: major telcos don’t own these cell towers any more. Specialist infrastructure companies typically build, own and maintain New Zealand's cell towers, while telcos like One NZ own and operate the radio equipment and electronics installed on those structures.

If you think about a mobile site like a road network, the tower company is the road owner and builder, so they provide the physical infrastructure. The telco is the transport operator - they own and run the vehicles (the radio equipment) that carry customers’ calls and data. Radio spectrum is like the traffic lanes those vehicles travel on, and the core network is the logistics hub that routes everything to its final destination. Adding spectrum is like adding another lane to a busy motorway, where it creates more space for everyone’s data to travel, reducing congestion and improving performance, especially at peak times. Multiple transport operators can use the same road infrastructure - just as multiple telcos can operate from the same tower.

There are two main ways to add more spectrum capacity to a mobile network.
The first is upgrading existing sites with additional equipment to broadcast new frequencies. This maximises the use of existing infrastructure, but there are limits to how much traffic a single site can handle, even with advanced technology.
The second option is building a new tower closer to where demand is highest. This shifts traffic from more distant sites, improves performance for users nearby, and frees up capacity on surrounding towers. That’s why new towers continue to be built in high-growth and high-traffic areas around the country.

In New Zealand there are a few big players in tower infrastructure:

• Fortysouth owns about 1,700 towers and covers roughly 98% of the population with passive infrastructure that hosts equipment from One NZ and other telcos.
• Connexa owns more than 2,500 towers and works with major mobile networks to deploy radio equipment to enable digital connectivity throughout New Zealand
• Rural Connectivity Group (RCG) owns about 500 towers and is a joint venture between One NZ, Spark, 2degrees and the government, building shared towers in rural and hard-to-reach areas, allowing all three telcos to use the same antennas and network kit on a shared structure.

That's important because having cell tower structures everywhere doesn’t automatically mean great mobile service. What counts for your coverage is the radio gear and radio spectrum or frequencies your telco has on those towers - that’s what your phone actually connects to. One NZ's network delivers 4G or 5G coverage to 99% of where Kiwis live, work, and play.

In December 2024, One NZ became the first company globally to go beyond traditional mobile coverage when it launched the One NZ Satellite service*. Satellite-to-mobile enables users with eligible phones and plans to use select apps and send TXTs via satellite to stay connected when outside of traditional cell-tower coverage wherever they can see the sky. Returning to our road analogy, this is like adding a capable 4x4 vehicle to the network - not as fast as travelling on a motorway, but able to reach the most remote corners of the country, even at the end of the roughest track.

We design our mobile network so that coverage from multiple cell sites overlaps wherever possible. This allows for a smooth experience as you move, with your device seamlessly handing over from one tower to the next - keeping your calls connected and video streams running without interruption. It also means when a tower is damaged or taken offline, like during a power outage after a severe weather event, the surrounding sites will help fill in some of the coverage gaps until we can get equipment to site to restore full service.

So, mobile coverage is delivered via our nationwide interconnected network, created with a complex array of physical and digital infrastructure. But in the end, the most important part of coverage is being connected to be able to work, live and play.

*One NZ Satellite: Use data on select apps and TXT/MMS in minutes. Requires eligible phone and plan, and line of sight to the sky. Limited app features. Paid Add-On may apply. Terms, fair use, standard MMS charges and capacity control applies. See https://one.nz/why-choose-us/satellite/