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If you've ever received an email or text hours after it was sent and privately raged at having missed a deadline, or twiddled your thumbs while waiting for a webpage to load, then you've been a victim of Internet latency.

Latency can occur for a number of reasons associated with disruption of an information lane such as an electronic wire or fiber optic cable, or from an overload of Internet-based messaging that can occur with increased network traffic.

As more and more forms of communication are carried over the Internet - email, Facebook, Twitter, cell phone messages, television broadcasts - andas more and more people use these forms of communication, the    need for systems that can handle very large amounts of Internet traffic has jumped.

Researchers at the Center for Integrated Access Networks, or CIAN, headquartered at the University of Arizona's College of Optical Sciences, are working to improve the efficiency of signal transmission through the    invisible network    of electronic and optic signals that forms the backbone of modern communication systems.

The UA-led center is the largest academic research program in optical networking in the U.S. today.

The center is co-led by the University of California, San Diegoand has seven additional partner institutions including Columbia University; California Institute of Technology; the University of California, Berkeley; University of California, Los Angeles; University of Southern California; Tuskegee University and Norfolk State University. The UA's Nasser Peyghambarian isthe center's director.

"CIAN is a type of National Science Foundation-funded program called an Engineering Research Center. These centers are selected in strategically important areas that relate to perceived national needs, including competitiveness in the future global  economy," said John Wissinger, a research professor in the UA's College of Optical Sciences who serves as testbed lead and associate director for industry collaboration for CIAN.

   "We are primarily working on optical networking technologies," said Massoud Karbassian, a post-doctoral researcher at the center'sTestbed for Optical Aggregation Networking, or TOAN lab.

   "Fiber optics is a medium for light transport," said Karbassian. In the same way that an electrical wire creates a pathway for electrons to travel, glass microfibers create a pathway for photons.

   "It's a medium for carrying information through laser beams, which generate photons. It's the backbone of modern communication: Wireless services we get at home, mobile phones and even enterprise networks are all connecting over the same infrastructure, which is the Internet."

Messages sent through the Internet start out as electronic signals sent from a device such as a computer, mobile phone or iPad.

"All these traffic types are aggregated, or brought together, at a network node," said Karbassian. "This requires collecting different types of traffic and handling their routing, reliability and security. This part is the key functionality of the whole network

infrastructure because it deals with collecting all these different types of traffic and handling them efficiently."

At network nodes, the electronic signals are converted to optical signals, which then are transmitted through optical fibers contained in underground cables - or undersea cables for trans-continental distances.

"For example, you're here in Arizona, and you're sending an email to your friend in England. Your email is probably sitting someplace like San Francisco, where the server is located, and your friend from England must           connect to that server to fetch the email," said Karbassian. "There is a need for connection between that server in San Francisco and the user in London."

At the end of the fiber-optic transport network, the message is collected in a server and converted back into an electronic signal that finally is transmitted to a receiver, for example your friend's email inbox.

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