The deal, still subject to completion, would make Arqiva the UK's largest independent provider of WiFi networks, competing with BT, Virgin Media and Sky's The Cloud.
Arqiva will pay £23.4m to buy 100% of Spectrum Interactive, the British firm which operates WiFi hotspots for clients including BAA, Nokia, Virgin Atlantic, Premier Inn and Whitbread.
The transmission operator said that the move will enable it to accelerate its wholesale mobile data business and provide a "highly scalable platform across the market".
With the growth in smartphones and mobile devices, there has been a huge increase in demand for mobile data and WiFi services. This demand is projected to rise by 65% per annum up to 2016, according to Arqiva.
BT operates the UK's largest WiFi estate, with more than 2m hotspots, but fellow internet service providers Virgin Media and Sky have recently made big strides into the market.
But unlike its rivals, Arqiva will not offer its WiFi networks direct to consumers, and instead wholesale the service to businesses and landlords.
Arqiva chief executive John Cresswell commented: "The acquisition of Spectrum Interactive positions Arqiva as one of the UK's largest WiFi hotspot providers and uniquely we would be the only wholesale provider with no associated retail service.
"We are well placed to help define the WiFi space for all UK landlords and business providers, allowing us to individually tailor services for our customers to meet the growing demand for data capacity."
"We can accelerate the roll-out of Arqiva's wholesale mobile data offer, whilst enhancing services provided to Spectrum Interactive's customers."
The Spectrum WiFi network is claimed to host more than 1.7m internet sessions at 2,100 premium locations every month.
Alongside WiFi, the firm also manages other wireless solutions, such as digital signage, internet kiosks and public printing services.
All employees of the Hertfordshire-based firm are expected to join Arqiva after the transaction completes.
"Spectrum Interactive is a solid business built by our investors, executives and employees, and as an independent player we have created a truly relevant market proposition," said the company's executive chairman Simon Alberga.
"Our customers and business will continue to be well served by this acquisition, and Arqiva's acquisition of Spectrum Interactive will ensure that our organisation will continue to lead and flourish in what is a highly innovative and competitive market."
Arqiva is seeking other revenue streams as this year will see the end of its £630m, multi-year project to switch the UK from analogue to digital television signals.
Alongside its emerging WiFi and mobile data services, the company is also a shareholder in YouView, the joint venture company that will soon launch a new hybrid Freeview set top box supporting TV and internet-based services.