Multipath Data Transmission for Wireless Thin Clients

At UBICOMM 2009, Systems Development Laboratory introduced research on the improvement of data transmission using multiple network paths for wireless thin clients with a presentation entitled "Multipath Data Transmission for Wireless Thin Clients."

Thin clients, which are known as effective solution for protecting critical data, have one main weakness. That is, their performance heavily depends on the performance of the networks that connect them to the server. Under poor network conditions, thin clients perform badly. This often occurs with a wireless thin client when the performance of the network varies for any reason, such as the distance from the thin client to the base station or the number of users.

We improved the quality of data transmission performed by a wireless thin client using a method of multipath data transmission, where the thin client simultaneously deploys two or more wireless-network access attempts to communicate with the server. We have TCP proxies called MCCP (Multipath Communication Control Proxy) that are located at the thin client and the server. A MCCP receives data from a remote desktop server and forwards them over multiple wireless-network connections to the MCCP on the other side (Fig. 1).

The algorithm that MCCPs used to send and receive data over multiple network connections is DAMT (Data-aware Multipath Transmission Algorithm).

Unlike existing multipath transmission algorithms that can only be used for reducing transmission latency (duplicate-and-forward algorithm) or aggregating network bandwidths (divide-and-forward algorithm), DAMT dynamically changes from duplicate-and-forward to divide-and-forward according to the size of the forwarded data. The DAMT algorithm can accomplish short latency in transmitting input signals and their responses and simultaneously increase the throughput of large desktop images (Fig. 2).

We showed results of some experiments obtained in a laboratory network environment. The results revealed that the DAMT algorithm successfully shortened the response to keyboard input to that of the duplicate-and-forward algorithm, and the speed at which the presentation file was played was as high as that of the divide-and-forward algorithm (Fig. 3).