Implicit Coordination Research Articles

Adaptive Coordinated Napping (CoNap) for Energy Saving in Wireless Networks

We propose a time slot based transmission strategy, referred to as adaptive coordinated napping (CoNap), for energy saving in cellular networks under time-varying traffic demand. In adaptive CoNap network, multiple neighboring base stations (BSs) form a cluster and each BS operates in either a transmit mode (TM) or a nap mode (NM) in each time slot. The dynamic assignment of TM and NM to each BS is implicitly coordinated among multiple BSs. This implicit coordination is realized by a binary general flickering pattern matrix (FPM) through adaptively selected mapping matrix (MM). To track the time-varying traffic demand, we develop an adaptive algorithm to dynamically select the appropriate MM from a predefined MM set by taking into account the network quality of service (QoS) requirement. Our numerical results based on a realistic energy consumption model in a cellular network show that as high as 40% saving can be achieved without compromising the network QoS.

Making smart use of excess antennas: Massive MIMO, small cells, and TDD

In this paper, we present a vision beyond the conventional Long Term Evolution Fourth Generation (LTE-4G) evolution path and suggest that time division duplexing (TDD) could be a key enabler for a new heterogeneous network architecture with the potential to provide ubiquitous coverage and unprecedented spectral area efficiencies. This architecture is based on a cochannel deployment of macro base stations (BSs) with very large antenna arrays and a secondary tier of small cells (SCs) with a few antennas each. Both tiers employ a TDD protocol in a synchronized fashion. The resulting channel reciprocity enables not only the estimation of large-dimensional channels at the BSs, but also an implicit coordination between both tiers without the need to exchange user data or channel state information (CSI) over the backhaul. In particular, during the uplink (UL), the BSs and SCs can locally estimate the dominant interference sub-space. This knowledge can be leveraged for downlink (DL) precoding to reduce intra- and inter-tier interference. In other words, the BSs and SCs “sacrifice” some of their degrees of freedom for interference rejection. Our simulation results demonstrate that the proposed architecture and precoding scheme can achieve a very attractive rate region compared to several baseline scenarios. For example, with 100 antennas at each BS and four antennas at each SC, we observe an aggregate area throughput of 7.63 Gb/s/km <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (DL) and 8.93 Gb/s/km <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> (UL) on a 20 MHz band shared by about 100 mobile devices.

A botnet-based command and control approach relying on swarm intelligence

Survivability and scalability are the main emerging challenges in command and control of ubiquitous networked entities operating in untrusted communication scenarios, due to the increasing sophistication of the detection and mitigation/defeating techniques together with the increasing number of elements to be controlled and their distribution over multiple heterogeneous communication infrastructures. Accordingly, this work focuses on a new more robust and scalable botnet-based command and control architecture, aiming at wiping off any rigid master-slave relationship and autonomizing the bot operating roles, with significant agility gains in the whole overlay communication infrastructure. It relies on swarm intelligence and in particular on stigmergic communication, ensuring spontaneous, implicit coordination and collaboration among the independent bot agents. The resulting architecture presents improved fault tolerance and dynamic adaptation to varying network conditions, by propagating control messages to any bot node through multiple short-range hops structured according to a dynamically built Degree Constrained Minimum Spanning Tree, whose distributed calculation is inspired to ant colony's foraging behavior. For this reason, it may constitute the basis for an evolutionary malware-based control and management scheme that can be used in several homeland security/defense scenarios where the botnet technology may be used as a support tool in strategic military or intelligence operations.

Co-ACT—a framework for observing coordination behaviour in acute care teams

BackgroundAcute care teams (ACTs) represent action teams, that is, teams in which members with specialised roles must coordinate their actions during intense situations, often under high time pressure and with...

A distributed scheduling framework based on selfish autonomous agents for federated cloud environments

Today, large-scale distributed Cloud computing infrastructures are often characterized by the fact that each participating organization, like a company in the free economy scenario, when making its resources available, will strive for reducing its own cost and for optimizing its own benefit, regardless of the consequences on the global Cloud’s welfare, in terms of effectiveness and performance losses. The selfish behavior of all these entities (end-users, Cloud providers, underlying enterprises/data centers), competing strategically for resources (distributed storage, processing power, bandwidth), motivates the use of game theory and autonomous agents for effective Multi-User Task Scheduling. Accordingly, we present a novel uncoordinated fully distributed scheduling scheme for federated cloud organizations, based on independent, competing, and self-interested job/task execution agents, driven by optimum social welfare criteria towards a Nash equilibrium solution. The agents’ behavior is also conditioned by marginal costs, to force some kind of implicit coordination between the (often conflicting) objectives of the various entities involved in the cloud. Due to its inherent parallel nature, such schema can provide a significantly better scalability in presence of a large number of tasks and resources involved into the scheduling system.

"Implicit Coordination in NPD Project Teams: Exploring its Dimensions, Antecedents and Consequences"

Cross-functional teams cope with the complexity and uncertainty of new product development (NPD) projects by coordinating the activities of their members. Recent research on team cognition suggests that effective teams are able to implicitly coordinate without overt communication or formal planning (traditional coordination mechanisms that are often associated with project delays and cost overruns). In this conceptual paper, we review the extant literature on NPD, team cognition, and proactive behavior to conceptualize implicit coordination (IC) in NPD projects. First, we propose a two-dimensional IC construct suggesting that IC is the result of both a complex cognitive process (anticipation, which refers to expectations about team members’ needs and constraints and the demands of the current task) and a behavioral process (dynamic adjustment, referring to the actions that team members choose based on their anticipations). Second, we identify factors that facilitate or impede the ability of team members to transform their anticipations into actions. We explain how these two processes contribute to improving NPD project performance. We discuss the theoretical and managerial implications and limitations of this approach; suggesting IC as a complementary method for coordinating tasks and activities rather than the sole coordination mechanism for the NPD project teams.

Affective Coordination: The Role of Team Emotional Interconnectedness

We articulate the role of team emotional interconnectedness in implicit coordination. Team emotional interconnectedness is defined as a team-level compilational construct, referring to each team member’s understanding of each other’s emotional states. Team emotional interconnectedness may or may not relate to team members having the same emotional state, but what is essential for team emotional interconnectedness to emerge is interconnectedness in team members’ emotional interactions. We explain how team emotional interconnectedness, as opposed to other types of collective emotions, provides explanations for implicit coordination processes beyond the explanations currently in the literature. Finally, we discuss how to measure team emotional interconnectedness, as well as the implications of team emotional interconnectedness for team emotion research.

What signal is your inspection team sending to each other? Using a shared collaborative interface to improve shared cognition and implicit coordination in error-detection teams

Coordination theory, created in a collaborative HCI context, has long emphasized the importance of implicit coordination. Such coordination is possible through interactivity design that creates shared cognition. Teams experience implicit coordination when they achieve tacit task coordination without direct or purposeful communication of task strategies among the participants, but this is impossible to achieve without shared cognition. Implicit coordination is often more effective than explicit coordination, and teams increasingly lack sufficient time or capabilities to coordinate explicitly; therefore, methods to foster implicit coordination could result in highly practical techniques to improve task performance. Implicit coordination, despite its promise, has not received much attention in the HCI literature. A particular problem we believe has hindered the application of implicit coordination is the dearth of objective measurement of implicit coordination and the related construct shared cognition. Teams have difficulty improving, implementing, and proving the value of implicit coordination without measurement.For our theoretical foundation, we use implicit coordination theory (ICT) to explain and predict how a simple shared interface in a group error-detection task can establish formalized group memory and group awareness, which foster the shared cognition necessary for implicit coordination to occur. To test ICT, we demonstrate innovative measurement of implicit coordination and shared cognition—without intrusive perceptual survey items—by leveraging measures from signal detection theory (SDT). We use the context of teams performing heuristic data-flow diagramming (HDFD) (which is similar to the Prepare, Collect, and Repair (PCR)-based process of heuristic evaluation) to measure the improved shared cognition and implicit coordination. Namely, we measured shared cognition with SDT's measure of response bias (c); we measured implicit coordination with SDT's measure of discrimination (d′). Supporting our ICT-based predictions, groups operating with a shared interface indeed experienced more shared cognition and implicit coordination—resulting in higher discrimination, more positive response bias, and more accurate hit rates and false-alarm rates than the control groups. Our results show great promise in making similar predictions, measurements, and improvements in other individual or group inspection tasks, which are prevalent in HCI development research and practice.

Spieltheoretische Analyse der (impliziten) Koordination von Benzinpreiserhöhungen am deutschen Tankstellenmarkt

Abstract In a recent study, the Federal Cartel Office (Bundeskartellamt) came to the conclusion that the oligopolistic market for petrol in Germany enables the oil companies to coordinate prices at petrol stations. In particular, prices are increased uniformly and on a regular basis on Fridays and just before public holidays. In this essay, possible coordination mechanisms, and their implications, will be analyzed with the aid of game-theoretical instruments. In line with the limits of game theory (Rubinstein, 1991), the empirical question of how (implicit) coordination mechanisms are applied in practice, and their political consequences, will not be examined in detail.

Combining coordination mechanisms to improve performance in multi-robot teams

Coordination is essential to achieving good performance in cooperative multiagent systems. To date, most work has focused on either implicit or explicit coordination mechanisms; while relatively little work has focused on the benefits of combining these two approaches. In this work we demonstrate that combining explicit and implicit mechanisms can significantly improve coordination and system performance over either approach individually. First, we use difference evaluations (which aim to compute an agent’s contribution to the team) and stigmergy to promote implicit coordination. Second, we introduce an explicit coordination mechanism dubbed intended Destination Enhanced Artificial State (IDEAS), where an agent incorporates other agents’ intended destinations directly into its state. The IDEAS approach does not require any formal negotiation between agents, and is based on passive information sharing. Finally, we combine these two approaches on a variant of a team-based multi-robot exploration domain, and show that agents using a both explicit and implicit coordination outperform other learning agents up to 25%.

Interstellar communication: The case for spread spectrum

Spread spectrum, widely employed in modern digital wireless terrestrial radio systems, chooses a signal with a noise-like character and much higher bandwidth than necessary. This paper advocates spread spectrum modulation for interstellar communication, motivated by robust immunity to radio-frequency interference (RFI) of technological origin in the vicinity of the receiver while preserving full detection sensitivity in the presence of natural sources of noise. Receiver design for noise immunity alone provides no basis for choosing a signal with any specific character, therefore failing to reduce ambiguity. By adding RFI to noise immunity as a design objective, the conjunction of choice of signal (by the transmitter) together with optimum detection for noise immunity (in the receiver) leads through simple probabilistic argument to the conclusion that the signal should possess the statistical properties of a burst of white noise, and also have a large time-bandwidth product. Thus spread spectrum also provides an implicit coordination between transmitter and receiver by reducing the ambiguity as to the signal character. This strategy requires the receiver to guess the specific noise-like signal, and it is contended that this is feasible if an appropriate pseudorandom signal is generated algorithmically. For example, conceptually simple algorithms like the binary expansion of common irrational numbers like π are shown to be suitable. Due to its deliberately wider bandwidth, spread spectrum is more susceptible to dispersion and distortion in propagation through the interstellar medium, desirably reducing ambiguity in parameters like bandwidth and carrier frequency. This suggests a promising new direction in interstellar communication using spread spectrum modulation techniques.

Proposal of Implicit Coordination Model for Performance Enhancement Using Sprint Zero

Abstract —Scrum model always welcome the new requirements from customer at any stage of software development. This situation creates problem for development team to meet estimated timelines. The Scrum development team is always under heavy workload and stress because of this situation. A high level of coordination among team members is required in order to overcome this work pressure and meet quality demands within estimated time and cost. Scrum model emphasis to coordinate through communication to cope with changing requirements. Scrum development is facing new challenges to meet high quality demands with critical timeline environment. The ability of a team to act intelligently in such situation is gaining key position for the survival and success of an organization. The goal of this paper is to highlight the role of implicit coordination helping the software development team members to act intelligently in time demand environment to achieve common goals. Implicit coordination among team members during sprint zero development can show significant improvement in team performance. This will help to achieve high quality product under heavy workload within estimated time period. A survey is conducted to validate the research i.e., implicit coordination has strong impact for successful implementation of Scrum methodology.

Multicultural Multiteam Systems

Work arrangements have changed over the last decade. Organizations are increasingly relying on teams from different organizations or from different parts of the same organization to accomplish organizational goals. Similar to teams, such multiple team systems must engage in collaborative behaviors such as coordination, cooperation, and information exchange. When multiple interacting teams are embedded in multiple societal cultural contexts, another layer of complexity is added. This article examines the effective use of four modes of coordination in multicultural, multiteam systems and the effects of societal culture on effective coordination. We conceptualize coordination to vary along two continua, time and explicitness, and we examine explicit and implicit coordination mechanisms. Contributions to the multiteam systems and multicultural team coordination literatures as well as future research opportunities are noted.

Schedule-driven intersection control

Model-based intersection optimization strategies have been widely investigated for distributed traffic signal control in road networks. Due to the form of “black-box” optimization that is typically assumed, a basic challenge faced by these strategies is the combinatorial nature of the problem that must be solved. The underlying state space is exponential in the number of time steps in the look-ahead optimization horizon at a given time resolution. In this paper, we present a schedule-driven intersection control strategy, called SchIC, which addresses this challenge by exploiting the structural information in non-uniformly distributed traffic flow. Central to our method is an alternative formulation of intersection control optimization as a scheduling problem, which effectively reduces the state space through use of an aggregate representation on traffic flow data in the prediction horizon. A forward recursive algorithm is proposed for solving the scheduling problem, which makes use of a dominance condition to efficiently eliminate most states at early stages. SchIC thus achieves near optimal solutions with a polynomial complexity in the prediction horizon, and is insensitive to the granularity of time resolution that is assumed. The performance of SchIC with respect to both intersection control and implicit coordination between intersections is evaluated empirically on two ideal scenarios and a real-world urban traffic network. Some characteristics and possible real-world extensions of SchIC are also discussed.

Facet personality and surface-level diversity as team mental model antecedents: Implications for implicit coordination.

Team mental models (TMMs) have received much attention as important drivers of effective team processes and performance. Less is known about the factors that give rise to these shared cognitive structures. We examined potential antecedents of TMMs, with a specific focus on team composition variables, including various facets of personality and surface-level diversity. Further, we examined implicit coordination as an important outcome of TMMs. Results suggest that team composition in terms of the cooperation facet of agreeableness and racial diversity were significantly related to team-focused TMM similarity. TMM similarity was also positively predictive of implicit coordination, which mediated the relationship between TMM similarity and team performance. Post hoc analyses revealed a significant interaction between the trust facet of agreeableness and racial diversity in predicting TMM similarity. Results are discussed in terms of facilitating the emergence of TMMs and corresponding implications for team-related human resource practices.

Adaptive coordination development in student anaesthesia teams: a longitudinal study

Although adaptive coordination has been highlighted by several studies, research dealing with how adaptive coordination develops is still rare. Thus, the aim of this study was to investigate the development of coordination mechanisms and their task-related adaptation in a longitudinal observation of medical simulation-based training of final year students. We recorded six anaesthesia teams during a sequence of four task scenarios, and each scenario comprised of a routine and a complication phase. After trained observers rated sub-tasks within each scenario for explicit and implicit coordination, statistical analysis revealed a statistically significant effect of previous scenarios on coordination development in the routine phases. While the amount of explicit coordination decreased, implicit coordination increased, revealing adaptive coordination as a skill developed through repeated group interaction. We conclude that anaesthesia training should consider cost- and patient safety-benefits of implicit and explicit coordination and focus on adaptive coordination. Practitioner Summary: Group coordination is crucial to anaesthesia team performance. Results of this longitudinal observation of six anaesthesia teams during four medical simulation-based training scenarios document that teams develop adaptive patterns of coordination. This study also demonstrates that adaptive coordination is a trainable skill within crisis resource management training.

Hallowed Grounds: The Role of Cultural Values, Practices, and Institutions in TMS in an Offshored Complex Engineering Services Project

The globalization of complex engineering services has resulted in physically dispersed teams that can no longer rely on the traditional and familiar oral transmission of engineering expertise nor can they assume knowledge of their team members' culture. Yet, such teams need to be able coordinate effectively the dispersed knowledge of team members. We know little about how cultural differences among engineering team members impact the coordination of dispersed knowledge, so called transactive memory systems (TMSs)-or “who knows what” and “who knows who knows what.” In this paper, we present a longitudinal case study of a dispersed, cross-cultural team involving U.S. and Romanian engineers. The cultural differences in values, practices, and institutions had a major impact on TMS indicators of specialization, coordination, and credibility. The paper demonstrates how the cultural differences impeded TMS development. The results provide insight into TMS as an implicit coordination mechanism in a global team. We provide advice in terms of interventions that can promote the development of TMS in a culturally diverse team.

Interference Analysis for Highly Directional 60-GHz Mesh Networks: The Case for Rethinking Medium Access Control

We investigate spatial interference statistics for multigigabit outdoor mesh networks operating in the unlicensed 60-GHz millimeter (mm) wave band. The links in such networks are highly directional: Because of the small carrier wavelength (an order of magnitude smaller than those for existing cellular and wireless local area networks), narrow beams are essential for overcoming higher path loss and can be implemented using compact electronically steerable antenna arrays. Directionality drastically reduces interference, but it also leads to deafness, making implicit coordination using carrier sense infeasible. In this paper, we make a quantitative case for rethinking medium access control (MAC) design in such settings. Unlike existing MAC protocols for omnidirectional networks, where the focus is on interference management, we contend that MAC design for 60-GHz mesh networks can essentially ignore interference and must focus instead on the challenge of scheduling half-duplex transmissions with deaf neighbors. Our main contribution is an analytical framework for estimating the collision probability in such networks as a function of the antenna patterns and the density of simultaneously transmitting nodes. The numerical results from our interference analysis show that highly directional links can indeed be modeled as pseudowired, in that the collision probability is small even with a significant density of transmitters. Furthermore, simulation of a rudimentary directional slotted Aloha protocol shows that packet losses due to failed coordination are an order of magnitude higher than those due to collisions, confirming our analytical results and highlighting the need for more sophisticated coordination mechanisms.

Duopoly Competition, Escape Dynamics and Non-Cooperative Collusion

In this paper, we study an imperfect monitoring model of duopoly under similar settings as in Green and Porter (1984), but here firms do not know the demand parameters and learn about them over time through the price signals. We investigate how a deviation from rational expectations affects the decision making process and what kind of behavior is sustainable in equilibrium. We find that the more common information firms analyze to update their beliefs, the more room is for implicit coordination. This might propagate escapes from the Cournot-Nash Equilibrium and the formation of cartels without explicit cooperative motives. In contrast to Green and Porter (1984), our results show that in a model with learning, breakdown of a cartel happens even without a demand shock. Moreover, in this model an expected price serves as an endogenous price threshold, which triggers a price war. Finally, by investigating the durations of the cooperative and price war phases, we find that in industries with a higher Nash equilibrium output and a lower volatility of firm-specific shocks, it is easier to maintain a cartel and harder to break it down.

Implicit coordination: Sharing goals with similar others intensifies goal pursuit

The current research explored whether sharing intentionality leads to implicit coordination, a situation in which isolated individuals independently adopt a similar standard of behavior. We propose that knowing that a given goal is experienced in common with other in-group members or similar others intensifies goal pursuit. Two experiments examined whether simply being aware that one's own individual goal was also being separately pursued by similar others results in more goal-congruent behavior. When a promotion goal was shared with similar others, participants produced greater promotion behaviors than when the same goal was shared with different others. Similarly, sharing a prevention goal with similar others led to greater prevention behavior than conditions where a) similar others had a different goal and b) different others shared the same goal. Overall, shared goals served as an intensifier of individual goal pursuit. We discuss shared goals as a foundation for the emergence of social synchrony in groups.