
Strategic Communication via Cascade
Multiple-Description Network
Rony Bou Rouphael and Maël Le Treust
ETIS UMR 8051, CY Cergy-Paris Université, ENSEA, CNRS,
6, avenue du Ponceau, 95014 Cergy-Pontoise CEDEX, FRANCE
Email: {rony.bou-rouphael ; mael.le-treust}@ensea.fr
Abstract—In decentralized decision-making problems, agents
choose their actions based on locally available information and
knowledge about decision rules or strategies of other agents.
We consider a three-node cascade network with an encoder,
a relay and a decoder, having distinct objectives captured by
cost functions. In such a cascade network, agents choose their
respective strategies sequentially, as a response to the former
agent’s strategy and in a way to influence the decision of the
latter agent in the network. We assume the encoder commits to a
strategy before the communication takes place. Upon revelation of
the encoding strategy, the relay commits to a strategy and reveals
it. The communication starts, the source sequence is drawn and
processed by the encoder and relay. Then, the decoder observes
a sequences of symbols, updates its Bayesian posterior beliefs
accordingly, and takes the optimal action. This is an extension of
the Bayesian persuasion problem in the Game Theory literature.
In this work, we provide an information-theoretic approach to
study the fundamental limit of the strategic communication via
three-node cascade network. Our goal is to characterize the
optimal strategies of the encoder, the relay and the decoder, and
study the asymptotic behavior of the encoder’s minimal long-run
cost function.
I. INTRODUCTION
We study a decentralized decision-making problem with re-
stricted communication between three agents with non-aligned
objectives. As depicted in Fig. 1, we consider a Cascade
channel where information travels from a strategic encoder
to a decoder through a strategic relay. We are interested in
designing an achievable multiple description coding scheme
that minimizes the encoder’s long run cost function subject to
the challenges imposed by the Cascade channel.
The problem of strategic communication originally emerged
in the game theory literature to address situations in economics
(lobbying, advertising, sales, negotiations, etc.). The game was
referred to as the sender-receiver game, and communication
was assumed to be perfect and unconstrained by any limits on
the amount of information transmitted. The Nash equilibrium
solution of the cheap talk game was investigated by Crawford
and Sobel in their seminal paper [1], in which the encoder
and the decoder are endowed with distinct objectives and
choose their coding strategies simultaneously. The Stackelberg
Maël Le Treust gratefully acknowledges financial support from INS2I
CNRS, DIM-RFSI, SRV ENSEA, UFR-ST UCP, INEX Paris Seine Initiative
and IEA Cergy-Pontoise. This research has been conducted as part of the
project Labex MME-DII (ANR11-LBX-0023-01).
PUσ µ τ
c2(U, V )c3(U, V )c1(U, V )
Vn
UnM1M2
R1R2
Fig. 1: Strategic Source Coding for Cascade Channel with
Successive Commitment.
version of the strategic communication game, referred to as
the Bayesian persuasion game, was formulated by Kamenica
and Gentzkow in [2], where the encoder is the Stackelberg
leader and the decoder is the Stackelberg follower choosing
its strategies as a response to the encoder’s strategy . In this
paper, we assume that the encoder commits to an encoding and
announces its commitment before observing the source. Then,
the relay commits to and announces a strategy accordingly.
If the relay was assumed to commit to a strategy before
the encoder, then the problem boils down to a strategic joint
source-channel coding of Shannon, like the one investigated in
[3]. Cascade source coding consists of compressing a source
sequence through an intermediate or relay node which then
reconstructs the source and transmits it to the next node. In [4],
Yamamoto considered the source coding problem for cascade
and branching communication systems, and established the
region of achievable rates for cascade systems and bounds
for the branching systems. Lossy source coding for cascade
communication systems was also considered in [5] where both
the relay and the terminal node have access to side information
and wish to reconstruct the source with certain fidelities.
In Bayesian persuasion, the encoder is considered to be an
information designer. In [6], information design with multiple
designers interacting with a set of agents is studied. In [7],
[8], the Nash equilibrium solution is investigated for multi-
dimensional sources and quadratic cost functions, whereas
the Stackelberg solution is studied in [9]. The computational
aspects of the persuasion game are considered in [10]. In
several recent contributions [11], [12], [13], Vora and Kulkarni
addressed the problem of extracting truthful information from
a strategic sender with an incentive to misreport information.
Modeled as a Stackelberg game in which the decoder is the
Stackelberg leader, authors investigate the region of achievable
rates of strategic communication between agents with distinct
arXiv:2210.00533v1 [cs.IT] 2 Oct 2022