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arxiv: 2602.16367 · v3 · pith:Q2FGCDZSnew · submitted 2026-02-18 · 💻 cs.NI · cs.ET

A Multihop Rendezvous Protocol for Cognitive Radio-based Emergency Response Network

Zahid Ali , Saritha Unnikrishnan , Eoghan Furey , Ian McLoughlin , Saim Ghafoor This is my paper

Pith reviewed 2026-05-21 13:04 UTC · model grok-4.3

classification 💻 cs.NI cs.ET
keywords cognitive radio networksmultihop rendezvouschannel hoppingnode discoveryemergency responsedual modular clock algorithmwireless coordination
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The pith

A multihop dual modular clock algorithm reduces rendezvous time by up to 24 percent in cognitive radio networks under worst-case conditions.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper tackles slow node discovery in multihop cognitive radio networks, where single-hop channel-hopping methods create extra delays and poor coordination across multiple nodes. It introduces the Multihop Dual Modular Clock Algorithm that lets each timeslot pick two channels and adds a simple three-way handshake to keep intermediate nodes aligned. Simulations test this under high primary user activity, uneven channel availability, and crowded networks. The results show rendezvous completes faster than prior methods, with gains reaching 24 percent. This approach targets quick link setup needed in emergency response scenarios where spectrum is shared and dynamic.

Core claim

The paper presents the Multihop Dual Modular Clock Algorithm (M-DMCA) as a systematic extension of modular clock rendezvous into multihop cognitive radio topologies. It preserves efficient coordination by enabling dual-channel selection per timeslot and adding a lightweight three-way handshake among intermediate nodes. Under simulation conditions that include high primary user activity, asymmetric channel availability, and dense network settings, M-DMCA cuts rendezvous time by up to 24 percent relative to existing approaches and proves suitable for timely node discovery in dynamic emergency response networks.

What carries the argument

The Multihop Dual Modular Clock Algorithm (M-DMCA), which extends single-hop modular clock rendezvous to multihop settings through dual-channel selection per timeslot and a lightweight three-way handshake for intermediate-node coordination.

If this is right

  • Rendezvous completes faster than single-hop algorithms when extended across multiple hops.
  • Intermediate nodes coordinate more reliably through the three-way handshake.
  • Performance holds under heavy primary user interference and uneven channel sets.
  • The scheme supports quick network formation required for emergency response operations.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Real-world tests could reveal whether the 24 percent gain persists once hardware constraints and actual spectrum sensing delays are included.
  • The dual-channel and handshake design might transfer to other multihop dynamic spectrum access settings such as sensor networks or vehicular links.
  • Further reduction in handshake overhead could be explored to improve performance in even denser topologies.
  • Integration with existing routing protocols could be examined to measure end-to-end latency benefits beyond pure rendezvous time.

Load-bearing premise

The simulation model under worst-case conditions of high primary user activity, asymmetric availability, and dense networks accurately reflects real deployment behavior, and the added three-way handshake introduces no meaningful extra delay or coordination failures.

What would settle it

A hardware experiment or field deployment in an actual cognitive radio network with real primary users and measured channel dynamics that shows whether rendezvous times remain 24 percent lower or increase due to practical coordination overhead.

Figures

Figures reproduced from arXiv: 2602.16367 by Eoghan Furey, Ian McLoughlin, Saim Ghafoor, Saritha Unnikrishnan, Zahid Ali.

Figure 1
Figure 1. Figure 1: However, designing efficient rendezvous mechanisms in [PITH_FULL_IMAGE:figures/full_fig_p001_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Distributed Clock Architecture and timeslot duration [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Two-way handshake (2-WH) 2) Three Way Handshake (3-WH): To address this limita￾tion, 3WH adds an extra confirmation step. Node A sends a D-REQ message, and upon receiving it, node B replies with a D-RESP containing its neighbor information. Node A then transmits a final D-ACK message to confirm reception of the D-RESP and share its updated neighbor list. This ensures that both nodes are immediately synchro… view at source ↗
Figure 4
Figure 4. Figure 4: Three-way handshake (3-WH) V. PERFORMANCE EVALUATION We simulated the proposed M-DMCA multihop rendezvous protocol using two half-slots within a single time slot and implemented both 2WH and 3WH mechanisms in the NS-3.35 simulator. The implementation models the behaviour of a CR network, including MAC, dual-channel operation, handshake mechanisms, and PR activity [7], [17]. For comparison, we also implemen… view at source ↗
Figure 8
Figure 8. Figure 8: Symmetric 10-CH with 85%PR (a) 2-WH vs (b) 3-WH [PITH_FULL_IMAGE:figures/full_fig_p005_8.png] view at source ↗
Figure 5
Figure 5. Figure 5: Symmetric 10-CH with 0%PR (a) 2-WH vs (b) 3-WH [PITH_FULL_IMAGE:figures/full_fig_p005_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: Symmetric 10-CH with 85%PR (a) 2-WH vs (b) 3-WH [PITH_FULL_IMAGE:figures/full_fig_p005_6.png] view at source ↗
Figure 10
Figure 10. Figure 10: Asym 10-CH with m=5 (a) 0%PR and (b) 85%PR [PITH_FULL_IMAGE:figures/full_fig_p005_10.png] view at source ↗
Figure 11
Figure 11. Figure 11: Asym 10-CH with m=2 (a) 0%PR (b) 85%PR D. Scalability with larger channel set and number of nodes with mixed PR activity Figures 12-14 illustrates the performance of M-DMCA un￾der 20 asymmetric channels (with m=2 and m=5) for scenarios involving 3, 10, and 20 nodes. As the number of channels increases, the rendezvous time increases significantly, as ob￾served in [PITH_FULL_IMAGE:figures/full_fig_p005_11.png] view at source ↗
Figure 12
Figure 12. Figure 12: Asym 20-CH with 0%PR (a) m=2 (b) m=5 (a) (b) [PITH_FULL_IMAGE:figures/full_fig_p006_12.png] view at source ↗
Figure 13
Figure 13. Figure 13: Asym 20-CH with 85%PR (a) m=2 (b) m=5 (a) (b) [PITH_FULL_IMAGE:figures/full_fig_p006_13.png] view at source ↗
Figure 14
Figure 14. Figure 14: Asym 20-CH with Mix PR (a) m=2 (b) m=5 VI. CONCLUSION This paper presented M-DMCA, a multihop dual modular clock–based rendezvous protocol for cognitive radio–enabled emergency response networks. By supporting dual-channel selection and incorporating a three-way handshake, M-DMCA significantly reduces rendezvous time under symmetric and asymmetric channel, varying channel similarity ratios, mixed and high… view at source ↗
read the original abstract

This paper addresses the challenge of efficient rendezvous in multihop cognitive radio networks, where existing channel-hopping algorithms designed for single-hop scenarios incur increased delay and coordination inefficiencies in multinode topologies. To overcome these limitations, we propose a Multihop Dual Modular Clock Algorithm (M-DMCA), which systematically extends modular clock-based rendezvous to multihop environments while preserving efficient channel coordination. The proposed scheme enables dual-channel selection per timeslot and incorporates a lightweight three-way handshake mechanism to improve coordination among intermediate nodes. Simulation results under worst-case conditions, including high primary user activity, asymmetric channel availability, and dense network settings, demonstrate that M-DMCA significantly reduces rendezvous time compared to existing approaches, achieving up to 24% improvement. These results demonstrate the suitability of M-DMCA for timely node discovery in dynamic emergency response scenarios.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 1 minor

Summary. The paper proposes the Multihop Dual Modular Clock Algorithm (M-DMCA) to address rendezvous delays in multihop cognitive radio networks for emergency response. It extends single-hop modular clock methods by enabling dual-channel selection per timeslot and adding a lightweight three-way handshake for coordination among intermediate nodes. Simulations under worst-case conditions (high primary user activity, asymmetric channel availability, dense networks) report up to 24% reduction in rendezvous time versus existing approaches.

Significance. If the simulation results hold after detailed verification of the protocol mechanics, the work could offer a targeted improvement for time-sensitive node discovery in dynamic multihop CR environments. The emphasis on worst-case scenarios strengthens practical relevance for emergency applications, though the purely empirical nature without analytical bounds or reproducible artifacts limits broader theoretical impact.

major comments (1)
  1. [Proposed Scheme and Simulation Results] The central 24% rendezvous-time reduction claim rests on simulations, yet the manuscript provides no equations, pseudocode, or description of how the three-way handshake messages are scheduled relative to the dual-channel hopping sequence or whether they consume extra timeslots. Under the stated high-PU and asymmetric-availability regimes, even one additional slot per hop would erase the net gain; this modeling detail is load-bearing for the performance result.
minor comments (1)
  1. [Abstract] The abstract refers to a 'lightweight' handshake without specifying message count, overhead relative to single-hop baselines, or how rendezvous time is precisely defined across multiple hops.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the constructive feedback on our manuscript. We address the major comment below and commit to revisions that strengthen the presentation of the protocol details.

read point-by-point responses

  1. Referee: [Proposed Scheme and Simulation Results] The central 24% rendezvous-time reduction claim rests on simulations, yet the manuscript provides no equations, pseudocode, or description of how the three-way handshake messages are scheduled relative to the dual-channel hopping sequence or whether they consume extra timeslots. Under the stated high-PU and asymmetric-availability regimes, even one additional slot per hop would erase the net gain; this modeling detail is load-bearing for the performance result.

    Authors: We agree that explicit modeling of the handshake scheduling is essential to substantiate the performance claims. The three-way handshake is integrated into the existing dual-channel selection mechanism such that control messages are exchanged on the second selected channel within the same timeslot as the primary hopping sequence, incurring no additional slot overhead. In the revised manuscript we will add the requested pseudocode, scheduling equations, and a timing diagram in Section 3 to make this integration fully transparent and to confirm that the reported gains remain valid under the simulated high-PU and asymmetric-availability conditions. revision: yes

Circularity Check

0 steps flagged

No circularity: protocol proposal and simulation evaluation are self-contained.

full rationale

The paper proposes M-DMCA as an extension of modular clock rendezvous to multihop settings via dual-channel selection per timeslot and a lightweight three-way handshake. The central performance claim (up to 24% rendezvous-time reduction) is obtained directly from simulation comparisons under stated worst-case conditions rather than any derivation, equation, or fitted parameter that reduces to its own inputs by construction. No self-definitional steps, fitted-input predictions, or load-bearing self-citations appear in the provided description or abstract. The evaluation relies on empirical simulation outputs, which are independent of the protocol definition itself and do not invoke uniqueness theorems or ansatzes from the authors' prior work.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The protocol claim depends on standard domain assumptions about channel dynamics in cognitive radio networks rather than new free parameters or invented entities.

axioms (1)
  • domain assumption Nodes operate in a multihop topology with possible asymmetric channel availability caused by primary user activity.
    This is invoked to justify the need for multihop coordination and is a standard premise in cognitive radio literature.

pith-pipeline@v0.9.0 · 5689 in / 1188 out tokens · 37624 ms · 2026-05-21T13:04:50.793523+00:00 · methodology

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score.

  1. Eliminating Premature Termination in Multihop Rendezvous for Cognitive Radio-based Emergency Response Network

    cs.NI 2026-05 unverdicted novelty 6.0

    MR-DMCA eliminates premature termination via coordinate-assisted validation and autonomous termination, achieving 100% neighbor discovery and up to 76% faster rendezvous time in 20-node simulations under high primary ...

Reference graph

Works this paper leans on

18 extracted references · 18 canonical work pages · cited by 1 Pith paper

  1. [1]

    Cognitive radio for disaster response networks: Survey, potential, and challenges,

    S. Ghafoor, P. D. Sutton, C. J. Sreenan, and K. N. Brown, “Cognitive radio for disaster response networks: Survey, potential, and challenges,” IEEE Wirel. Commun., vol. 21, no. 5, pp. 70–80, 2014

    work page 2014

  2. [2]

    Post- Disaster Communications: Enabling Technologies, Architectures, and Open Challenges,

    M. Matracia, N. Saeed, M. A. Kishk, and M. S. Alouini, “Post- Disaster Communications: Enabling Technologies, Architectures, and Open Challenges,” IEEE Open J. Commun. Soc., vol. 3, 2022

    work page 2022

  3. [3]

    Federal Communications Commission,http://www.it.kth.se/ ∼jmitola/ Mitola Dissertation8 Integrated.pdf, 2003

    work page 2003

  4. [4]

    Rendezvous for cognitive radios,

    N. C. Theis, R. W. Thomas, and L. A. DaSilva, “Rendezvous for cognitive radios,” IEEE Trans. Mob. Comput., vol. 10, no. 2, pp. 216–227, Feb. 2011

    work page 2011

  5. [5]

    A dual modular clock algorithm for cognitive radio-based emergency response network,

    Z. Ali, S. Ghafoor, S. Unnikrishnan, E. Furey, and I. McLoughlin, “A dual modular clock algorithm for cognitive radio-based emergency response network,” inProceedings of the 2025 IEEE 22nd Consumer Communications & Networking Conference (CCNC), pp. 1–6, IEEE, 2025

    work page 2025

  6. [6]

    Jump-stay rendezvous algorithm for cognitive radio networks,

    H. Liu, Z. Lin, X. Chu, and Y . W. Leung, “Jump-stay rendezvous algorithm for cognitive radio networks,” *IEEE Transactions on Parallel and Distributed Systems*, vol. 23, no. 10, pp. 1867–1881, IEEE, 2012

    work page 2012

  7. [7]

    A cognitive radio-based fully blind multihop rendezvous protocol for unknown environments,

    S. Ghafoor, C. J. Sreenan, and K. N. Brown, “A cognitive radio-based fully blind multihop rendezvous protocol for unknown environments,” Ad Hoc Networks, vol. 107, Oct. 2020

    work page 2020

  8. [8]

    A distributed network coded control channel for multihop cognitive radio networks,

    A. Asterjadhi, N. Baldo, and M. Zorzi, “A distributed network coded control channel for multihop cognitive radio networks,”IEEE Network, vol. 23, no. 4, pp. 26–32, 2009

    work page 2009

  9. [9]

    Rendezvous protocols based on message passing in cognitive radio networks,

    J. Jia and Q. Zhang, “Rendezvous protocols based on message passing in cognitive radio networks,”IEEE Transactions on Wireless Communi- cations, vol. 12, no. 11, pp. 5594–5606, 2013

    work page 2013

  10. [10]

    Bracer: A distributed broadcast protocol in multi- hop cognitive radio ad hoc networks with collision avoidance,

    Y . Song and J. Xie, “Bracer: A distributed broadcast protocol in multi- hop cognitive radio ad hoc networks with collision avoidance,”IEEE Transactions on Mobile Computing, vol. 14, no. 3, pp. 509–524, 2015

    work page 2015

  11. [11]

    ASAA: Multihop and Multiuser Channel Hopping Protocols for Cognitive-Radio-Enabled Internet of Things,

    D. D. Onthoni, P. K. Sahoo, and M. Atiquzzaman, “ASAA: Multihop and Multiuser Channel Hopping Protocols for Cognitive-Radio-Enabled Internet of Things,”IEEE Internet of Things Journal, vol. 10, no. 9, pp. 8305–8318, 2023

    work page 2023

  12. [12]

    Efficient rendezvous for heterogeneous interference in cognitive radio networks,

    Z. Gu, T. Shen, Y . Wang, and F. C. Lau, “Efficient rendezvous for heterogeneous interference in cognitive radio networks,” IEEE Trans. Wireless Commun., vol. 19, no. 1, 2019

    work page 2019

  13. [13]

    Frequency-Gateway Based Differential Rendezvous Algorithm for Cognitive Radio Networks,

    M. Yuan, Y . Chu, and W. Guo, “Frequency-Gateway Based Differential Rendezvous Algorithm for Cognitive Radio Networks,” inProc. IEEE Wireless Commun. Netw. Conf. (WCNC), Apr. 2024

    work page 2024

  14. [14]

    Cyclostationary signatures in practical cognitive radio applications,

    P. D. Sutton, K. E. Nolan, and L. E. Doyle, “Cyclostationary signatures in practical cognitive radio applications,” J. Sel. Areas Comm, 2008

    work page 2008

  15. [15]

    Primary radio user activity models for cognitive radio networks: A survey,

    Y . Saleem and M. H. Rehmani, “Primary radio user activity models for cognitive radio networks: A survey,” Journal of Network and Computer Applications, vol. 43, 2014

    work page 2014

  16. [16]

    Efficient discovery of spectrum opportunities with MAC-layer sensing in cognitive radio networks,

    H. Kim and K. Shin, “Efficient discovery of spectrum opportunities with MAC-layer sensing in cognitive radio networks,” IEEE Trans. Mob. Comput., vol. 7, 2008

    work page 2008

  17. [17]

    Tricia Chigan,CRCN Simulator, Available at: https://faculty.uml.edu/ Tricia Chigan/Research/CRCN Simulator.htm, 2024

    work page 2024

  18. [18]

    BonnMotion: A Mobility Scenario Gen and Analysis Tool,

    BonnMotion, “BonnMotion: A Mobility Scenario Gen and Analysis Tool,” [Online]. Available: https://bonnmotion.sys.cs.uos.de/index.shtml

    work page