Abstract: Embodiments of this invention relate to methods and apparatus for establishing additional simultaneous packet data network (PDN) connections between a User Equipment (UE) and an evolved packet core network (EPC) over an untrusted WiFi network. The UE is attached to the EPC through a security gateway over a first PDN connection over which the UE is authenticated and has established an Internet Key Exchange Security Association (IKE SA) and a first Internet Protocol Security SA (IPSec SA). The UE then establishes an additional PDN connection using a new IKE request/response exchange or an enhanced IKE CREATE_CHILD_SA exchange that is cryptographically protected using algorithms and keys negotiated during the first PDN connection, hence improving delay and battery life of the UE as the UE no longer needs, for each additional PDN connection, to negotiate an individual IKE SA and to authenticate the UE.

Abstract: Embodiments of this invention relates to methods, and apparatus for establishing additional simultaneous packet data network, PDN, connections between a User Equipment, UE, and the evolved packet core network, EPC, over an untrusted WiFi network. The UE is attached to the EPC through a security gateway over a first PDN connection over which the UE is authenticated and has established an IKE Security Association, SA and a first IPSec SA. The UE then establishes an additional PDN connection using a new IKE request/response exchange or an enhanced IKE CREATE_CHILD_SA exchange that is cryptographically protected using the algorithms and keys negotiated during the first PDN connection, hence improving the delay and the UE battery life as the UE no longer needs, for each additional PDN connection, to negotiate an individual IKE SA and to authenticate the UE.

Abstract: An environment-friendly type polypropylene foam plastic and preparation method thereof. The foam plastic utilizes plastic elastomer as basis material, and a third monomer is led in as crosslinking co-agent to carry out crosslinking and control degradation products. Foam plastic profile products are made by graft copolymerizing said monomer on polypropylene and crosslinking, and then internal mixing, open mixing, sheeting and foam molding with compatibilizer, filler, nucleating agent, crosslinking agent and foaming agent.