A method of a first network node for conserving network resources in a mobile communications network, the method being implemented by a first network node, the method comprising: determining that each of a plurality of members of a device user group, DUG, has been inactive for more than a predetermined period of time, wherein the plurality of members includes a User Equipment, UE, associated with an existing UE session, and the UE is a machine to machine, M2M, type device; in response to determining that each of the plurality of members has been inactive for more than the predetermined period of time: identifying a subset of information related to the existing UE session, wherein the subset of information can be used to create a new UE session associated with the DUG, wherein the subset of information comprises UE IP Address, Page Information, and Mobility Management Entity, MME, or Serving Gateway, SGW, Information; storing the subset of information; and releasing network resources associated with the existing UE session at the first network node, wherein the DUG is not notified of said releasing; transmitting a release cause code to a second network node wherein the release cause code causes the second network node to release local network resources at the second network node without notifying the DUG about releasing the local network resources; receiving a request to transfer data to the DUG; creating a new UE session using the stored subset of session information and establishing network resources associated with the new UE session at the first and second network nodes; transferring the data to the DUG using the new UE session; and requesting a diameter credit control application, DCCA, session for the DUG. determining that each of a plurality of members of a device user group, DUG, has been inactive for more than a predetermined period of time, wherein the plurality of members includes a User Equipment, UE, associated with an existing UE session, and the UE is a machine to machine, M2M, type device; in response to determining that each of the plurality of members has been inactive for more than the predetermined period of time: identifying a subset of information related to the existing UE session, wherein the subset of information can be used to create a new UE session associated with the DUG, wherein the subset of information comprises UE IP Address, Page Information, and Mobility Management Entity, MME, or identifying a subset of information related to the existing UE session, wherein the subset of information can be used to create a new UE session associated with the DUG, wherein the subset of information comprises UE IP Address, Page Information, and Mobility Management Entity, MME, or Serving Gateway, SGW, Information; storing the subset of information; and releasing network resources associated with the existing UE session at the first network node, wherein the DUG is not notified of said releasing; transmitting a release cause code to a second network node wherein the release cause code causes the second network node to release local network resources at the second network node without notifying the DUG about releasing the local network resources; storing the subset of information; and releasing network resources associated with the existing UE session at the first network node, wherein the DUG is not notified of said releasing; transmitting a release cause code to a second network node wherein the release cause code causes the second network node to release local network resources at the second network node without notifying the DUG about releasing the local network resources; receiving a request to transfer data to the DUG; creating a new UE session using the stored subset of session information and establishing network resources associated with the new UE session at the first and second network nodes; transferring the data to the DUG using the new UE session; and requesting a diameter credit control application, DCCA, session for the DUG.