An evolved packet core, EPC, for serving a user equipment, UE, comprising: a centralized EPC having a home subscriber server, HSS, configured to store authentication information and to authenticate and identify the UE; a first distributed EPC having: a first serving gateway, SGW, configured to be coupled to a first radio node and configured to anchor a user session for the UE and to route user data to and from the UE through the first radio node, a first packet data network gateway, PGW, configured to be coupled between the first SGW and a network and configured to anchor an internet protocol, IP, session for the UE and to route the user data between the first SGW and the network, and a first mobility management entity, MME, configured to receive an authentication of the UE from the HSS and coordinate establishment of the user session and the IP session; and a second distributed EPC having: a second SGW configured to be coupled to a second radio node and configured to route the user data to and from the second radio node, a second PGW configured to be coupled between the second SGW and the network and configured to route the user data between the second SGW and the network, and a second MME; wherein, when the UE transitions from being served by the first radio node to being served by the second radio node, the first MME is configured to: instruct the first PGW to release connection resources for the user session and to hold IP resources for the IP session, and inform the HSS of the release of the connection resources and of the hold of the IP resources; and wherein, when the UE initiates connectivity with the second radio node, the second MME is configured to: receive a re-authentication of the UE from the HSS, and coordinate with the HSS and the first MME to establish a tunnel between the first PGW and the second PGW according to the IP resources and through which the user data can be routed from the UE to the second PGW, to the first PGW, and to the network. a centralized EPC having a home subscriber server, HSS, configured to store authentication information and to authenticate and identify the UE; a first distributed EPC having: a first serving gateway, SGW, configured to be coupled to a first radio node and configured to anchor a user session for the UE and to route user data to and from the UE through the first radio node, a first packet data network gateway, PGW, configured to be coupled between the first SGW and a network and configured to anchor an internet protocol, IP, session for the UE and to route the user data between the first SGW and the network, and a first mobility management entity, MME, configured to receive an authentication of the UE from the HSS and coordinate establishment of the user session and the IP session; and a first serving gateway, SGW, configured to be coupled to a first radio node and configured to anchor a user session for the UE and to route user data to and from the UE through the first radio node, a first packet data network gateway, PGW, configured to be coupled between the first SGW and a network and configured to anchor an internet protocol, IP, session for the UE and to route the user data between the first SGW and the network, and a first mobility management entity, MME, configured to receive an authentication of the UE from the HSS and coordinate establishment of the user session and the IP session; and a second distributed EPC having: a second SGW configured to be coupled to a second radio node and configured to route the user data to and from the second radio node, a second PGW configured to be coupled between the second SGW and the network and configured to route the user data between the second SGW and the network, and a second MME; a second SGW configured to be coupled to a second radio node and configured to route the user data to and from the second radio node, a second PGW configured to be coupled between the second SGW and the network and configured to route the user data between the second SGW and the network, and a second MME; wherein, when the UE transitions from being served by the first radio node to being served by the second radio node, the first MME is configured to: instruct the first PGW to release connection resources for the user session and to hold IP resources for the IP session, and inform the HSS of the release of the connection resources and of the hold of the IP resources; and instruct the first PGW to release connection resources for the user session and to hold IP resources for the IP session, and inform the HSS of the release of the connection resources and of the hold of the IP resources; and wherein, when the UE initiates connectivity with the second radio node, the second MME is configured to: receive a re-authentication of the UE from the HSS, and coordinate with the HSS and the first MME to establish a tunnel between the first PGW and the second PGW according to the IP resources and through which the user data can be routed from the UE to the second PGW, to the first PGW, and to the network. receive a re-authentication of the UE from the HSS, and coordinate with the HSS and the first MME to establish a tunnel between the first PGW and the second PGW according to the IP resources and through which the user data can be routed from the UE to the second PGW, to the first PGW, and to the network.