This week I've been taking a closer look at how LTE networks will be used in practice. One of the big differences to current 3G and 3.5G networks is that LTE is fully based on IP, i.e. there is no longer a circuit switched core network for voice telephony. Today, it makes sense for 3G/3.5G devices to attach to the network without requesting an IP address since they are (still) mostly used for voice telephony. In LTE networks, however, a device without an IP address is completely useless. Hence, the LTE network attach procedure already includes the assignment of an IP address. Consequently, an LTE device will always have an IP address. For people coming from the LAN/WLAN world this is nothing new. For people in the cellular industry, however, this is revolutionary. The 3G/3.5G procedure of 'establishing a packet call', a term coined with the old thinking of establishing a circuit switched connection for a voice call in mind, will thus become history with 4G. Many people in the industry will have to change their picture of the mobile world to accommodate for this.