Overview
Helios is a NGI (Next Generation Internet) project with three goals:
(1) build a high speed IP/WDM test link based on the HiPeR-L protocol and compare its performance with current operational IP/SONET/WDM links;
(2) develop traffic models for networks with high-speed links; and
(3) test and explore two distributed computing applications made feasible by high-speed network links.

The Operational Network
The NCNI network is a gigapop serving universities and others in Carolina. NCNI, which has a strong research program, seeks to advance the exploration and development of leading-edge network technologies, engineering, and applications through advanced network services and early deployment of technologies. The NCNI network serves as a base for Helios: packet header collection is carried out on this network, the testbeds share some facilities with the operational network, and new Helios technology will have the opportunity to move into the operational network.

Funding and Equipment
Helios has funding of $1.8 million from DARPA as part of their NGI program. Lucent's Optical Area Network Group has provided $1.2 million in hardware, a WaveStar OLS 40G WDM system with 4 wavelengths, each 2.5 gb/s; two wavelengths are used by Helios and two are used by the NCNI operational network.

The Helios Team and Funding
The Helios team is made up of people from NCNI, Bell Labs Statistics and Data Mining Research, Bell Labs Optical Local Area Network Research, University of North Carolina Computer Science, North Carolina State University Computer Science Research, and Lucent's Optical Area Network Group.

Network Computing Applications
Two network computing applications are being investigated. The goal is to determine how high-speed networking affects distributed computational environments. One application is S-Net-Helios, a distributed network traffic analysis application. On this testbed, data collected on the NCNI network will be analyzed using the S-Net architecture. The second is a real time meteorology application. We are developing an application testbed network carrying IP traffic between MCNC, and NCSU. The testbed architecture will consist of interconnected gigabit access networks interconnected with dWDM optical facilities with 2 wavelengths at 2.5 Gbps each.

Traffic Analysis
Packet header data is being collected on the NCNI network and analyzed. The goal is to study network performance and to build statistical models for TCP transfer requests. Analysis will be carried out on the S-Net-Helios testbed.

IP over WDM
We are building a testbed for IP over light based on the HiPeR-l MAC protocol. HiPeR-l was designed to exist in an optical single-hop architecture with access nodes interconnected to a passive star coupler to form a broadcast star topology. The goal is to develop several innovative features making it more valuable relative to other work in this area in terms of scalability, collision-free scheduling, adaptability and support for multicast, and differentiated services.

The work includes basic MAC layer protocol design, development of scheduling algorithms for optical transmission, network traffic monitoring, and design and implementation of optical network interface card (ONIC). We further undertake experimental evaluation of the prototype systems in testbed networks, in a local area (LAN), and benchtop settings. A testbed will support the development and experimentation of an extended version of the HiPeR-l MAC protocol developed and analyzed at NCSU. HiPeR-l was designed to exist in an optical single-hop architecture with access nodes interconnected to a passive star coupler to form a broadcast star topology. A third (benchtop) testbed supporting fast tunable laser applications will also be established.