The end is near for 3G in the US, as AT&T prepares to shut down its network next week, with T-Mobile and Verizon to follow suit within the calendar year.\nIt\u2019s a changeover long in the making, according to experts. The carriers, facing a spectrum shortage, have wanted to reuse 3G spectrum for newer-generation network technology for years, and the shortfall has only gotten worse as 5G begins to roll out. Verizon stopped supporting new 3G devices in 2018, and pushed back a planned 2019 3G shutdown until the end of 2022, according to IDC research manager Jason Leigh.\n\u201cThe overwhelming argument is \u2018we need spectrum it\u2019s the lifeblood of 5G\u2019, and if you\u2019re seeing diminishing use on your 3G network, it\u2019s not very cost efficient [to maintain],\u201d he said.\n\nThe spectrum between roughly 850MHz and 2GHz used for 3G is prime wireless real estate for 5G, according to Gartner director analyst Bill Menezes.\n\u201cThe mid-band low-band spectrum they\u2019re using is a natural fit for 5G,\u201d he said. \u201cThey want to re-farm that spectrum.\u201d\nThat re-farming, however, is likely to prove a problem for at least some of the carrier\u2019s existing enterprise customers, particularly those in the IoT space. Plenty of older devices, particularly in the utility and energy industries, still use 3G, and updating them to newer standards isn\u2019t a seamless process.\n\u201cMost of the enterprise-relevant IoT devices [affected by the shutdown] are IoT,\u201d said Menezes. \u201cThey have really long life-cycles, and they might take a lot more labor to get them updated.\u201d\nDevices in remote areas, or those that are rarely serviced\u2014oil pipeline instrumentation, for example\u2014are likely to be the biggest headaches in terms of replacement, he added, but there are still plenty of other 3G IoT devices out there.\nAnd despite the fact that the carriers\u2019 intentions to shut down 3G have been public for some time, Menezes said that the cellular IoT ecosystem is a complex one, meaning that not just the carriers but IoT service providers as well have to communicate changes to end-users.\nGiven the sheer number of moving parts, it\u2019s no surprise that there have been some apparent hiccups, according to Leigh, though most of that is attributable to managed service providers, not the carriers themselves.\n\u201cI think [the carriers] have done as fair a job as they can in communicating this,\u201d he said. \u201c[But] is there still gonna be some pain? Absolutely.\u201d\nIt\u2019s important to remember that the stakes, for the carriers, are high, given their ongoing efforts to gain more of a share of the enterprise market, Leigh noted.\n\u201cGiven how important the enterprise business is to carriers, the outreach has already been there,\u201d he said.\nExactly how much inconvenience the 3G shutdown causes for a given enterprise user could be a great opportunity for those users to re-evaluate their relationships with particular vendors, according to Menezes.\n\u201cHow well they\u2019ve handled this should be a sign for how well they\u2019re going to handle future changes,\u201d he said.