It's by far the dominant connectivity option for M2M - currently accounting for the vast majority of connections - but 2G (mostly GSM) cellular may soon under pressure in some markets where spectrum is scarce and operators are looking to 'refarm' their old 2G allocations for LTE mobile broadband well before the decade is out. Robin Duke-Woolley, CEO of M2M specialist, Beecham Research, talks to Ian Scales about the relative costs of 2, 3 and 4G and WiFi. WiFi's low costs and other characteristics make it attractive for the home networking 'Internet of Things' end of the market, but will its likely increasing use as a carrier technology begin to make it a viable alternative to cell - at least in some circumstances?