Ki-Suk Kweon

Timer-Based Bloom Filter Aggregation for Reducing Signaling Overhead in Distributed Mobility Management

Distributed mobility management (DMM) is a promising technology to address the mobile data traffic explosion problem. Since the location information of mobile nodes (MNs) are distributed in several mobility agents (MAs), DMM requires an additional mechanism to share the location information of MNs between MAs. In the literature, multicast or distributed hash table (DHT)-based sharing methods have been suggested; however they incur significant signaling overhead owing to unnecessary location information updates under frequent handovers. To reduce the signaling overhead, we propose a timer-based Bloom filter aggregation (TBFA) scheme for distributing the location information. In the TBFA scheme, the location information of MNs is maintained by Bloom filters at each MA. Also, since the propagation of the whole Bloom filter for every MN movement leads to high signaling overhead, each MA only propagates changed indexes in the Bloom filter when a pre-defined timer expires. To verify the performance of the TBFA scheme, we develop analytical models on the signaling overhead and the latency and devise an algorithm to select an appropriate timer value. Extensive simulation results are given to show the accuracy of analytical models and effectiveness of the TBFA scheme over the existing DMM scheme.

Terminal-centric distribution and orchestration of IP mobility for 5G networks

Advances in radio access technologies and mobile terminals are fueling the growth of Internet traffic via mobile networks. The upcoming 5G era, with a new 5G radio technology and increased utilization of heterogeneous networking, will further accelerate mobile data usage. One of the pillars of mobile network architecture is IP mobility management, which is currently based on centralized data path management. In this article, we first describe the efficiency issues of the centralized approach. We then discuss multiple dimensions of distributing the mobility functions, and suggest how the mobile terminal can utilize them in orchestration for efficient communication over a 5G flat mobile network.

Energy efficient IP reachability for push service in NATted LTE systems

As smartphones have become increasingly pervasive, large amount of mobile data traffic has started to overwhelm the networks. Surprisingly, according to [1], the main cause of network congestion in cellular networks today is not only the data traffic generated by smartphones, but also the underlying signaling from the smartphone applications such as push email, instant messaging, and social network services. Such signaling is inevitable as the service providers need to provide always connected service to users. Among multiple signaling burdens, we consider “keepalive” message that is widely used to make a persistent IP connection for most push services in order to keep Network Address Translation (NAT) tables refreshed. Keepalive messages not only overburden the cellular network due to accompanied signaling traffics, but also significantly reduce the battery life of smartphones. In this paper, we propose a method that makes the push service possible without a keepalive mechanism for NATted network system. When the application servers have data to send to some UE given that the UEs information such as IP address and port number is not available in the servers, they first request this information from the network instead of maintaining a persistent IP connection. Our proposal helps increasing the battery life of the smartphone and relieving the overhead of the network. Simulation results show that the proposed scheme can reduce both battery power consumption and signaling traffic of UE by more than about 30% and 20%, respectively, compared to the keepalive-based legacy mechanism.