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NextG cellular networks are designed to meet Quality of Service requirements for various applications in and beyond smartphones and mobile devices. However, lacking introspection into the 5G Radio Access Network (RAN) application and transport layer designers are ill-poised to cope with the vagaries of the wireless last hop to a mobile client, while 5G network operators run mostly closed networks, limiting their potential for co-design with the wider internet and user applications. This paper presents NR-Scope, a passive, incrementally-deployable, and independently-deployable Standalone 5G network telemetry system that can stream fine-grained RAN capacity, latency, and retransmission information to application servers to enable better millisecond scale, application-level decisions on offered load and bit rate adaptation than end-to-end latency measurements or end-to-end packet losses currently permit. Our experimental evaluation on various 5G Standalone base stations demonstrates NR-Scope can achieve less than 0.1% throughput error estimation for every UE in a RAN. The code is available at https://github.com/PrincetonUniversity/NR-Scope.
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L4Span: Spanning Congestion Signaling over NextG Networks for Interactive Applications
Design for low latency networking is essential for tomorrow’s interactive applications, but it is essential to deploy incrementally and universally at the network’s last mile. While wired broadband ISPs are rolling out the leading queue occupancy signaling mechanisms, the cellular Radio Access Network (RAN), another important last mile to many users, lags behind these efforts. This paper proposes a new RAN design, L4Span, that abstracts the complexities of RAN queueing in a simple interface, thus tying the queue state of the RAN to end-to-end low-latency signaling all the way back to the content server. At millisecond-level timescales, L4Span predicts the RAN’s queuing occupancy and performs ECN marking for both low-latency and classic flows. L4Span is lightweight, requiring minimal RAN modifications, and remains 3GPP and O-RAN compliant for maximum ease of deployment. We implement a prototype on the srsRAN open-source software in C++. Our evaluation compares the performance of low-latency as well as classic flows with or without the deployment of L4Span in various wireless channel conditions. Results show that L4Span reduces the one-way delay of both low-latency and classic flows by up to 98%, while simultaneously maintaining near line-rate throughput.
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- PAR ID:
- 10639936
- Editor(s):
- Lutu, Andra; Zhang, Ying
- Publisher / Repository:
- ACM International Conference on emerging Networking EXperiments and Technologies (CoNEXT)
- Date Published:
- Journal Name:
- The proceedings of the ACM on networking
- ISSN:
- 2834-5509
- Subject(s) / Keyword(s):
- 5G Network Congestion Control ECN Feedback L4S Architecture
- Format(s):
- Medium: X
- Location:
- Hong Kong
- Sponsoring Org:
- National Science Foundation
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