A study commissioned by UK regulator Ofcom said mobile coverage inside buildings is under threat from a number of factors over the next few years, including the use of higher frequency bands.
Other factors include stricter building regulations, poorer device sensitivity in multi-band smartphones and growing user expectations, according to the study conducted by Real Wireless.
However, the good news is that mobile operators are tackling the problem as shown by recent announcements from UK operators aboutf how they plan to extend indoor coverage. Both Vodafone and O2 have said they will reach 98 per cent indoor data coverage by end 2015.
The study identifies a number of options such as MIMO antenna deployment and allocation of sub 1GHz spectrum that could deepen in-building coverage.
However, in certain circumstances due to variations in construction materials and building shapes, delivering a mobile signal does become problematic.
Moreover, users increasingly demand high-quality indoor coverage particularly for data consumption.