pen to have 3GPP modems, those can still access the 3GPP networks via local gateways such as mobile handsets or CPEs. The 3GPP is working on many 3GPP standards updates accommodate smart objects, or support MTC, as we described in Section 6.5.2. In this section we will talk about some of the issues in more detail. The 3GPP access is a lucrative access for smart objects due to very widespread out- doors and indoors coverage, especially on 2G networks, and also quite reasonable power consumption figures for idle nodes (especially when the 3GPP modem is turned off). This means that while smart phones are perhaps not such keen data users in 2G accesses (including IPv6 use), the smart objects may very well be. Hence it can happen that IPv6 sees widespread adoption on 2G due to IoT! If 2G becomes a very popular access for IoT, it can have significant implications for cellular networks. In particular, it could lossify the upgrade strategies in a way that 2G may not be that easy to turn off - in an attempt to replace it with 3G or LTE - if there are huge numbers of (inexpensive) smart objects using 2G and without 3G capability [56]. Address Space Consumption If the estimates stated by the OECD materialize, and the 50 billion devices connect to wireless networks and the 500 billion in total to the Internet, it is quite easy to see that numbering that device population with a mere 4 billion IPv4 addresses would be challenging to say the least. For the IPv6 address space the numbering of IoT is not a Deploying IPv6 in 3GPP Networks major challenge, as even the 500 billion addresses is just a minuscule part of the whole address space. Even for a network operator in practice, remembering the 64-bit prefix per PDN Con- nection approach used in 3GPP and described in Section 4.1.2, we can calculate that one /37 prefix can number one hundred million smart objects having in total one hun- dred million unique PDN Connections. Considering a typical /32 prefix allocation for a cellular operator, the one hundred million smart objects 