Some technical standardization work has been done to enable such roaming services, with some of Apple’s latest iPads including SIMs that make it easier for users to switch between mobile networks. A leading SIM supplier, Gemalto, is supplying reprogrammable SIMs for smart watches. The first steps have been taken in this direction in the Netherlands, which in 2014 allowed SIMs to be issued by organizations other than mobile network operators, such as utilities and car companies84. The GSMA has developed standards for remote M2M device management. Mobile operators, including China Unicom and Telefónica, are supporting these standards85.Greater flexibility and competition would be possible if large IoT operators were able to act like mobile virtual network operators – not least because they could then have wholesale access to mobile networks86. The German network regulator, Bundesnetzagentur, consulted on the market for International Mobile Subscriber Identifiers (IMSIs) in late 201487. An OECD analyst estimated that if German carmakers were able to issue their own SIMs and rent spare capacity on mobile networks, they could save USD 2.5 billion per year through lower prices and more flexible contracts88. The Belgian communications regulator BIPT is also consulting on the national number plan89.The European Conference of Postal and Telecommunications Administration’s (CEPT’s) Electronic Communications Committee has recommended that SIMs whose IMSI can be remotely updated should be implemented as soon as possible, and that CEPT countries consider greater flexibility in assigning Mobile Network Codes (MNCs) to IoT service providers. It has also encouraged the ITU-T to consider updating Recommendation E.212 to explicitly allow this flexibility, as well as to plan for the future use of MNCs to support a broader range of services90. These changes have been under consideration in ITU-T Study Group 2.3.5.3 Addressing and numbering IoT devices may have globally unique and routable communications addresses (requiring a very large protocol address space, such as that of IPv6). Or, they could have an address assigned by a gateway that allows limited inter-network connectivity. Or, they could make use of local networks only, to share data with -- and receive instructions from -- a nearby controller, such as a personal computer, smart phone, or specialized management device. In that case, a globally-unique address is not required.Enabling peer-to-peer connections between devices can increase the reliability of communications, compared with requiring a large and complex global network. Peer-to-peer also matches the common use case of an individual discovering and interacting with nearby devices. But where devices must be globally reachable – most likely, via the Internet – a large address space is required to individually identify each device. The number of unallocated addresses for the current version of the Internet Protocol (IPv4) is extremely limited, but the new version (IPv6) being rolled out by ISPs around the world has enough addresses for almost any conceivable number of devices91. The transition from IPv4 to IPv6 has taken longer than expected, and policy-makers may need to continue encouraging the transition in the medium term. The U.S. government, for example, has set up a Federal IPv6 Task Force to move all federal agencies from IPv4 to IPv6, also prompting the private sector to do the same. Many other countries have also set up IPv6 task forces to encourage national transitions.For any IoT identification scheme, there will be trade-offs between performance, scalability, interoperability, efficiency, privacy, ease of authentication, reliability, flexibility, extendibility, and mobility support. Along with IPv6 addresses, the other main identification standards being developed are from the International Organization for Standards (ISO) and GS1, as well as ITU-T Recommendation E.212 for the use of IMSI for machine-to-machine communications92. The latter has the advantage of a well-developed authentication, payment and global roaming framework, operated by mobile telephony providers, with hardware security based on SIMs. IoT applications using public networks, particularly mobile networks, will require ITU-T Recommendation E.164 (on telephone numbering plans) in the short-to-medium term and will provide a bridge to an all-IP solution in the longer term. The relevance of the E.164 telephone numbering plan for IoT applications was further noted by the European Communications Office Trends in Telecommunication Reform 2016 87 Chapter 3