Impact of reusable communication mechanisms and hierarchies in cooperation strategies and incentives

This deliverable builds upon the work on cooperation strategies and incentives of task T3.4 presented in deliverable D3.4 [1] and presents the updates in the work reported there. The focus of the task is on mechanisms that exhibit strong cooperation aspects. Cooperation can refer to interactions between multiple networking functionalities for achieving a common objective. It can also refer to conditions where multiple, even totally contradicting, objectives of different networking functionalities as well as multiple objectives of different network segments and/or different services need to be taken into account. The granularity of cooperation also varies; it can be contained within the boundaries of a single Network Empowerment Mechanism (NEM) but it can also refer to inter-NEM relationships; in the latter case the mechanism guiding the cooperation between different and independent NEMs is referred to as a UMF Core Mechanism One notable difference compared to deliverable D3.4 is that in the current deliverable this discrimination between mechanisms exhibiting cooperation aspects and "residing" within a single NEM (intra-NEM) and mechanisms guiding inter-NEM interactions is made clear. While the intra-NEM mechanisms also have the potential to be generalised and adapted for guiding inter-NEM interactions, UMF Core Mechanisms are by definition designed in a way that they are generic and -to a certain extent- NEM agnostic so they can be easily reused in different contexts. It is worth pointing that the UMF core mechanisms mentioned in this deliverable, all belong to the Coordination block (COORD) and have been highlighted in the D2.2 deliverable [2]. It is the role of Chapter 2 to present the project developed NEMs and highlight the cooperation aspects that guide their behaviour. As it will be shown, the developed NEMs vary significantly in the network and service context as well as in their objectives and the methodology they use to implement the required, cooperative in nature, functionality. This functionality -as mentioned above- can refer to meeting multiple objectives of different networks and/or services but also to the condition that the NEMs are distributed in nature, with cooperation needed to guide the interactions between the disjoint NEM components, even if it is a same unique objective they are working towards to. In Chapter 3 we present the project developed UMF Core Mechanisms. Here, contrary to WP2 - Unified Management Framework, we present the mechanisms not in an abstract and generic way but when applied to specific network scenarios and to specific NEMs. One can consider what is presented here as instantiations of the UMF Core Mechanisms so their applicability and performance can be quantified. Hierarchical optimization, synchronous control theory and centralized multi-objective optimization are considered here, spanning almost the whole range of the project developed UMF (COORD) Core Mechanisms. Chapter 4 focuses on integration aspects and attempts to present the logic on how the above described NEMs and instantiations of COORD Core Mechanisms should be considered together when needed so by the demands of a networking scenario. Towards this end we first present a set of factors that would need to be considered so that conflicting situations on a per-NEM/mechanism instantiation level can be avoided. As it will be shown there exist multiple factors that need to be considered; here we will present the logic behind them, the actual combination of these factors and their importance/ranking is an on-going activity within WP2. In conclusion, this deliverable shows that cooperation is a very important aspect both at an intra-NEM level and also at an inter-NEM level and mechanisms to guide this cooperation are absolutely essential so that multiple networking functionalities can work properly together towards a greater goal rather than uncontrollably competing with each other leading to conflicts, instabilities and oscillatory behaviours. The effectiveness of the considered mechanisms is shown through simulations, analytical modelling and proof of concept prototypes. The specific instantiations of COORD Core Mechanisms are an indication of their reusability and examples of successful mapping of mechanisms, from a specification point of view (as in WP2 documents) to an actual scenario/NEM-basis point of view. Further results with respect to the reusability of the mechanisms are expected in Deliverable D3.9 "Handbook on optimization, learning, operation and cooperation methods" which by its nature will provide a benchmarking of mechanisms; this will provide practical guidelines to guide the actual selection of mechanisms to achieve cooperation both at an intra-NEM but also -and most important- at an inter-NEM level, subject to performance, network and service environment and other constraints.