Energy Profile Aware Routing

A Quantitative Survey of the Power Saving Potential in IP-Over-WDM Backbone Networks

“…The reported savings for the different algorithms are in a very narrow range (29% to 34%, IP layer savings, see Table XI). The other PAR-related works we have listed in Table XI ([74], [17], [82]) report savings consistent with that finding. A notable exception is Fisher et al [83] who report much higher savings (40% to 80%, probably applicable to IP router line cards, which would correspond to IP layer savings around 30% to 60%).…”

“…Furthermore, some of the algorithms proposed in [80] are evaluated on a testbed by Tego et al [98], which so far has only rarely been done for research in this area. For the saving potential of PAR approaches we will however refer to the more recent work by the same author [81], as it evaluates different PAR algorithms 17 It is interesting to point out that we identified the same high sensitivity to the ratio of the required link capacity over the available interface capacity in [96] (referred to as demand/linerate ratio) in the context of optical bypass. 18 Note that similar approaches have been referred to in other works as Energy Aware Routing (EAR), Energy Aware Adaptive Routing (EAAR) or Green Routing.…”

“…The second paragraph covers works that do quantify the isolated and combined power saving potential in backbone networks, and highlights some of their shortcomings. The main works are listed in Table I. In the work by Restrepo et al [17], power reduction approaches are broken down into three levels depending on the area of application: (i) on circuit level (such as the use of dynamic voltage or frequency scaling techniques), (ii) on equipment level (e.g., replacing components by their counterpart in the optical domain) and (iii) on network level (network planning for efficiency, e.g. by using optical bypass).…”

“…The practical advantage of the simple turn off strategy lays in the fact that all decisions can be taken locally and require no logical topology changes, which is especially attractive for network operators where network stability is critical. A significant drawback includes the fact that the actual saving potential relies heavily on the amount of bundled links being prevalent in current and future core networks 17 . A more elaborate approach, which we will refer to as Power Aware Routing (PAR) 18 , is to not wait until a line card is completely idle, but instead pro-actively reroute traffic so that traffic of lightly loaded links is moved to links with spare capacity.…”

Using an analytical power model to survey power saving approaches in backbone networks

“…As a result, the rerouted traffic will likely not be routed over the shortest path anymore; but under the correct constraints could still result in energy savings. Examples of such power-aware routing can be found in [30], [31], [32], [33]. One final aspect to consider with respect to sleep modes is the timing associated with powering-up and -down of (sub)equipment.…”