A user equipment, UE, comprising: means for transmitting an attach request message to a mobility management entity, MME, wherein the attach request message comprises: an indication to the MME that the UE supports an Evolved Packet System, EPS, Mobility Management, EMM, state EMM-REGISTERED without Packet Data Network, PDN, connection, and an Evolved Packet System, EPS, Session Management, ESM, Dummy Message instead of a Packet Data Network, PDN, Connectivity Request message, wherein the ESM Dummy Message indicates to the MME that the UE requests attachment to the network without establishment of a PDN connection; and means for receiving an attach accept message transmitted from the MME, wherein the attach accept message comprises: an indication to the UE that the MME supports the EMM state EMM-REGISTERED without PDN connection, and an ESM Dummy Message that indicates to the UE that the MME accepts a request of the UE to attach to the network without establishment of PDN connectivity; wherein the ESM Dummy Message consists of: a field for indicating a protocol discriminator; a field for indicating an EPS bearer identity; a field for indicating a procedure transaction identity; and a field for indicating an ESM Dummy Message identity. means for transmitting an attach request message to a mobility management entity, MME, wherein the attach request message comprises: an indication to the MME that the UE supports an Evolved Packet System, EPS, Mobility Management, EMM, state EMM-REGISTERED without Packet Data Network, PDN, connection, and an Evolved Packet System, EPS, Session Management, ESM, Dummy Message instead of a Packet Data Network, PDN, Connectivity Request message, wherein the ESM Dummy Message indicates to the MME that the UE requests attachment to the network without establishment of a PDN connection; and an indication to the MME that the UE supports an Evolved Packet System, EPS, Mobility Management, EMM, state EMM-REGISTERED without Packet Data Network, PDN, connection, and an Evolved Packet System, EPS, Session Management, ESM, Dummy Message instead of a Packet Data Network, PDN, Connectivity Request message, wherein the ESM Dummy Message indicates to the MME that the UE requests attachment to the network without establishment of a PDN connection; and means for receiving an attach accept message transmitted from the MME, wherein the attach accept message comprises: an indication to the UE that the MME supports the EMM state EMM-REGISTERED without PDN connection, and an ESM Dummy Message that indicates to the UE that the MME accepts a request of the UE to attach to the network without establishment of PDN connectivity; an indication to the UE that the MME supports the EMM state EMM-REGISTERED without PDN connection, and an ESM Dummy Message that indicates to the UE that the MME accepts a request of the UE to attach to the network without establishment of PDN connectivity; wherein the ESM Dummy Message consists of: a field for indicating a protocol discriminator; a field for indicating an EPS bearer identity; a field for indicating a procedure transaction identity; and a field for indicating an ESM Dummy Message identity. a field for indicating a protocol discriminator; a field for indicating an EPS bearer identity; a field for indicating a procedure transaction identity; and a field for indicating an ESM Dummy Message identity.