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Low latency is a requirement for a variety of interactive network applications. The Internet, however, is not optimized for latency. We thus explore the design of wide-area networks that move data at nearly the speed of light in vacuum. Our cISP design augments the Internet’s fiber with free-space microwave wireless connectivity over paths very close to great-circle paths. cISP addresses the fundamental challenge of simultaneously providing ultra-low latency while accounting for numerous practical factors ranging from transmission tower availability to packet queuing. We show that instantiations of cISP across the United States and Europe would achieve mean latencies within 5% of that achievable using great-circle paths at the speed of light, over medium and long distances. Further, using experiments conducted on a nearly-speed-of-light algorithmic trading network, together with an analysis of trading data at its end points, we show that microwave networks are reliably faster than fiber networks even in inclement weather. Finally, we estimate that the economic value of such networks would substantially exceed their expense. 

Interactive mobile applications like web browsing and gaming are known to benefit significantly from low latency networking, as applications communicate with cloud servers and other users’ devices. Emerging mobile channel standards have not met these needs: general-purpose channels are greatly improving bandwidth but empirically offer little improvement for common latency-sensitive applications, and ultra-low-latency channels are targeted at only specific applications with very low bandwidth requirements. We explore a different direction for wireless channel design: utilizing two channels – one high bandwidth, one low latency – simultaneously for general-purpose applications. With a focus on web browsing, we design fine-grained traffic steering heuristics that can be implemented in a shim layer of the host network stack, effectively exploiting the high bandwidth and low latency properties of both channels. In the special case of 5G’s channels, our experiments show that even though URLLC offers just 0.2% of the bandwidth of eMBB, the use of both channels in parallel can reduce page load time by 26% to 59% compared to delivering traffic exclusively on eMBB. We believe this approach may benefit applications in addition to web browsing, may offer service providers incentives to deploy low latency channels, and suggests a direction for the design of future wireless channels. 

Header bidding (HB) is a relatively new online advertising technology that allows a content publisher to conduct a client-side (i.e., from within the end-user’s browser), real-time auction for selling ad slots on a web page. We developed a new browser extension for Chrome and Firefox to observe this in-browser auction process from the user’s perspective. We use real end-user measurements from 393,400 HB auctions to (a) quantify the ad revenue from HB auctions, (b) estimate latency overheads when integrating with ad exchanges and discuss their implications for ad revenue, and (c) break down the time spent in soliciting bids from ad exchanges into various factors and highlight areas for improvement. For the users in our study, we find that HB increases ad revenue for web sites by 28% compared to that in real-time bidding as reported in a prior work. We also find that the latency overheads in HB can be easily reduced or eliminated and outline a few solutions, and pitch the HB platform as an opportunity for privacy-preserving advertising. 

A new space race is imminent, with several industry players working towards satellite-based Internet connectivity. While satellite networks are not themselves new, these recent proposals are aimed at orders of magnitude higher bandwidth and much lower latency, with constellations planned to comprise thousands of satellites. These are not merely far future plans — the first satellite launches have already commenced, and substantial planned capacity has already been sold. It is thus critical that networking researchers engage actively with this research space, instead of missing what may be one of the most significant modern developments in networking. In our first steps in this direction, we find that this new breed of satellite networks could potentially compete with today’s ISPs in many settings, and in fact offer lower latencies than present fiber infrastructure over long distances. We thus elucidate some of the unique challenges these networks present at virtually all layers, from topology design and ISP economics, to routing and congestion control.