Cisco and Japan’s new fourth network operator Rakuten Mobile have announced the successful launch of an inter-network roaming service between the cellco and fellow operator KDDI’s mobile networks across Japan. In a press release, the vendor noted that the LTE roaming service – which is reportedly defined by 3GPP and based on the S10 signalling interface standard – is being used within Cisco’s Virtual Ultra Packet Core to link to mobility management entities (MMEs) between the two operators. ‘The MMEs track relevant user data sessions to ensure smooth handover from one operator’s network to the next. The data path will be managed by connecting the KDDI network with Cisco’s System Architecture Evolution Gateway VNF supporting a Control and User Plane Separation architecture,’ the statement read. The Virtual Ultra Packet Core is designed to help Rakuten Mobile improve the end user experience by ensuring voice/data connectivity when moving between the respective networks. Given that the new fourth operator is reliant on other network operators to achieve ‘national’ coverage, Rakuten hopes the Cisco solution will enable it to offer an uninterrupted mobile broadband connection while it builds out its own network infrastructure.