Rajesh Roy

Degraded-Service-Aware Multipath Provisioning in Telecom Mesh Networks

We investigate multipath provisioning in telecom mesh networks. The objectives are to minimize link loads and support degraded service, namely guarantee a fraction of the requested bandwidth even in case of a link failure.

Performance of 10G-EPON

10G-EPON system specifications have reached the end of the development cycle, with the release of the final standard version. Recent announcements of first practical 10G-EPON demonstrations [1, 2] indicate rapid adoption of these specifications by system vendors. Given the growing interest in 10G-EPON, it is useful to examine the worst-case scenario performance of this new first-mile access network in both downstream and upstream channels. Due to the number of technical changes introduced to 10G-EPON when compared with 1G-EPON, the obtained performance figures are substantially different from those of its predecessor. The results presented in this article have been obtained through an analytical model and confirmed by detailed simulation.

Telecom Mesh Network Upgrade to Manage Traffic Growth

Telecom mesh networks require periodic upgrades to support increasing traffic. Such upgrades, which are referred to as network engineering (NE), determine the additional network resources that must be provided to meet the network performance while minimizing the incremental network cost. To facilitate such network growth, considering dynamic routing, attention should be directed toward critical cut sets rather than individual links. Our analysis in this paper shows how capacity exhaustion of critical cut sets indicates urgency of the need for upgrading a mesh network. To handle traffic growth, we also introduce a new parameter called the network-cut exhaustion probability. This parameter is efficient and appropriate to assist incremental growth of the existing network as well as new network design. Finally, we provide an algorithm to calculate the urgency and the pointers to specific locations that require upgrade under desired performance constraints.

10G-EPON efficiency

After the success 1G-EPON in broadband access network, both industry and academia have shown great interest in the standardization of next-generation 10G-EPON. As the specification is in the final stage, it is imperative to examine the performance of this new first-mile access technology.

Managing Traffic Growth in Telecom Mesh Networks (Invited Paper)

Telecom mesh networks require periodic upgrades to support increasing traffic. Such upgrades, which are known as network engineering (NE), determine the network resources that must be provided to meet the network performance while minimizing the network cost. To handle traffic growth, we introduce a new parameter namely network-cut exhaustion probability. We develop a method to calculate this parameter and evaluate specific upgrade requirements of telecom mesh network.

Sender Side Intelligence for TCP Throughput Enhancement in Wired-Cum-Wireless Network

Performance of the TCP Congestion Control Algorithm has been the focus of research over the last decade. In this paper we propose modifications to TCP Congestion Control to improve its performance in wired-cum-wireless networks. The key idea to determine the Optimal Congestion Window for a TCP Sender, in a particular network scenario (that corresponds to the fair share of that connection) and keep this congestion window a constant to a point where the fair share in the network has changed considerably from the instance of the calculation of the size of the last window. At this point, the TCP Congestion Window is recalculated according to the nature of new scenario. The proposed mechanism is particularly effective over wireless links, which have an inherently loss-prone nature, as Modified TCPs congestion window being independent of packet losses (be it corruption losses or it congestion losses), keeps transmitting at the same rate as before.

P-SIGMA: security aware paging in end-to-end mobility management scheme

Mobile users need to maintain end-to-end connections when changing subnets. Handoff across networks often causes delay and loss of packets and make end users vulnerable to security threats that may lead to disruptions. In this paper, we design P-SIGMA, a delay and security-hardened, disruption-tolerant and signalling cost-effective end-to-end mobility management scheme by incorporating paging in SIGMA, an internet protocol diversity-based end-to-end transport layer mobility management scheme. P-SIGMA can detect and mitigate disruptions against two most common security threats: session hijacking and freeloading. We also propose a signalling cost analysis model for paging and a recovery-time model for attacks. To demonstrate performance improvement, we compare P-SIGMA with SIGMA and show the speed at which P-SIGMA can detect attacks (security breaches). We observe that P-SIGMA has lower signalling than SIGMA while maintaining all the benefits of a transport layer mobility management scheme. P-SIGMA can also detect paging related security threats with a small detection time without incurring any additional signalling.

Traffic growth and network engineering in optical mesh networks

Backbone networks employing optical meshes require periodic upgrades to support increasing traffic. Network-cut exhaustion probability is used to guide the upgrade (namely network engineering) of such networks.