CellBricks

Democratizing Cellular Access

CellBricks is a novel cellular architecture that lowers the barrier to entry for
new operators — small or large, trusted or untrusted.

Markets in which competition thrives are good for both consumers and innovation but, unfortunately, competition is not thriving in the increasingly important cellular market. We propose CellBricks, a novel cellular architecture that lowers the barrier to entry for new operators by enabling users to consume access on-demand from any available cellular operator — small or large, trusted or untrusted. CellBricks achieves this by moving support for mobility and user management (authentication and billing) out of the network and into end hosts. These changes, we believe, bring valuable benefits beyond enabling competition: they lead to a cellular infrastructure that is simpler and more efficient.

The Design

To realize CellBricks we face three key technical challenges:

  • How do we ensure secure attachments in the absence of mutual trust between bTelcos and users/brokers?
  • How do we minimize disruption to users' connections when switching between bTelcos?
  • How do we ensure secure billing and QoS enforcement in the absence of mutual trust between bTelcos and users/brokers?

These challenges are addressed with the following design components:

  • On-demand authentication and authorization. A UE (U) may request service from a bTelco (T1) when it comes within range of T1. The request initiates the attachment protocol (SAP) where the broker (B) can securely authenticate and authorize U to T1.
  • Verifiable billing and QoS. Periodically, U and T1 independently send verifiable and tamper-proof usage reports to B. These reports summarize both the bandwidth used and connection quality that U received. At some later time, T1 bills B based on the usage reports.
  • Host-driven mobility. U may come in the range of bTelco T2 and may wish to switch from T1 to T2. To do so, U simply repeats the same authentication and authorization steps with T2 as it did with T1 and then switches to T2. To handle this situation without requiring coordination between bTelcos, we employ host-based mobility procedures (e.g., MPTCP) that does not disrupt users’ application-level sessions.

Below is an overview of the attachment, billing/QoS, and mobility process in CellBricks, depicting the key events and message exchanges happen during the SAP, MPTCP, and billing protocol.

We've built and evaluated CellBricks with a prototype and emulation over real-world infrastructure, showing that its benefits come at little-to-no cost in performance, with application performance between -1.95% to 3.1% of that achieved by current cellular infrastructure. For more on the CellBricks' motivation, design, and results, check out our SIGCOMM'21 paper.

Publications


Zhihong Luo, Silvery Fu, Mark Theis, Shaddi Hasan, Sylvia Ratnasamy, Scott Shenker
Democratizing Cellular Access with CellBricks, Artifact
Association for Computing Machinery's Special Interest Group on Data Communications (SIGCOMM’21).


CellBricks Code

GitHub repositories

CellBricks Talks

Team

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Zhihong Luo

PhD Student @ UCB

Zhihong Luo

Zhihong Luo is a PhD student in the NetSys lab at UC Berkeley, USA.

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Silvery Fu

PhD Student @ UCB

Silvery Fu

Silvery Fu is a PhD student in the NetSys lab at UC Berkeley, USA.

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Mark Theis

Undergraduate Researcher @ UCB

Mark Theis

Mark Theis is a researcher at the NetSys Lab at UC Berkeley, USA.

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Shaddi Hasan

Professor @ VT

Shaddi Hasan

Shaddi Hasan is an incoming assistant professor at Virginia Tech, USA.

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Christian Maciocco

Principal Engineer @ Intel Labs

Christian Maciocco

Christian Maciocco is a Principal Engineer and Director of Telecom Systems Research in Intel Labs working on platform and communications research in Software Defined Network (SDN) and Network Function Virtualization (NFV).

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Sylvia Ratnasamy

Professor @ UCB

Sylvia Ratnasamy

Sylvia Ratnasamy is a professor of computer science at UC Berkeley, USA.

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Scott Shenker

Professor @ UCB

Scott Shenker

Scott Shenker is a professor of computer science at UC Berkeley, USA.

Sponsors