Sampath Rangarajan

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In-band full-duplex (IBFD) operation has emerged as an attractive solution for increasing the throughput of wireless communication systems and networks. With IBFD, a wireless terminal is allowed to transmit and receive simultaneously in the same frequency band. This tutorial paper reviews the main concepts of IBFD wireless. Because one the biggest practical(More)
This paper describes the design and implementation of a network virtualization substrate (NVS) for effective virtualization of wireless resources in cellular networks. Virtualization fosters the realization of several interesting deployment scenarios such as customized virtual networks, virtual services, and widearea corporate networks, with diverse(More)
Femto cells are a cost-effective means of providing ubiquitous connectivity in future broadband wireless networks. While their primary purpose has been to improve coverage in current solutions, their decreased cell sizes in turn also provide improved cell capacity through increased spatial reuse. The demand for bandwidth-intensive IP services will soon(More)
Given that full duplex (FD) and MIMO both employ multiple antenna resources, an important question that arises is how to make the choice between MIMO and FD? We show that optimal performance requires a combination of both to be used. Hence, we present the design and implementation of MIDU, the first MIMO full duplex system for wireless networks. MIDU(More)
As the growth of mobile video traffic outpaces that of cellular network speed, industry is adopting HTTP-based adaptive video streaming technology which enables dynamic adaptation of video bit-rates to match changing network conditions. However, recent measurement studies have observed problems in fairness, stability, and efficiency of resource utilization(More)
This paper describes the design and implementation of a network virtualization substrate <b>NVS</b>) for effective virtualization of wireless resources in WiMAX networks. Virtualization fosters the realization of several interesting deployment scenarios such as customized virtual networks, virtual services and wide-area corporate networks, with diverse(More)
Network MIMO (netMIMO) has potential for significantly enhancing the capacity of wireless networks with tight coordination of access points (APs) to serve multiple users concurrently. Existing schemes realize netMIMO by integrating distributed APs into one ``giant'' MIMO but do not scale well owing to their global synchronization requirement and overhead in(More)
This paper presents the design and implementation of a Java package called Filterfresh for building replicated fault-tolerant servers. Maintaining the correctness and integrity of replicated servers is supported by a GroupManager object instantiated with each replica to form a logical group. The Group Managers use a Group Membership algorithm to maintain a(More)
Deploying and managing wide-area network services is exceptionally challenging. Despite having servers at many locations, a <i>service provider</i> must rely on an underlying best-effort network; a <i>network provider</i> can offer services over its own customized network, but only within limited footprint. In this paper, we propose Cabernet (Connectivity(More)
Future mobile carrier networks need to address the predicted growth in mobile traffic volume which is expected to have explosive growth in the next years mainly driven by video and web applications [1]. Based on the expected capacity demand increase, mobile network operators (MNOs) are required to increase capital (CAPEX) and operational expenses (OPEX)(More)