In this paper, we introduce a new multiplane optical switching fabric structure based on a baseline type switching network. The new structure is built from symmetrical and asymmetrical optical switching elements. This new architecture can be extended to structures of greater size (it means capacity as a number of inputs and outputs). To compare different types of switching architectures, we define the cost of an appropriate structure as the number of its passive and active optical elements. Generally, structure with smallest number of these elements constitutes a cheaper solution. We also introduce a strict-sense nonblocking conditions for the proposed multiplane structure and compare them with an optical baseline multiplane switching networks of the same capacity. We show that for most capacities of the switching network, the new multiplane architecture is a cheaper solution than the multiplane baseline network even when the number of planes in the new architecture is greater than the number of one planes in the baseline structure — cost of the whole new structure expressed as the number of passive and active optical elements is fewer than baseline network of the same capacity.

In this paper we describe the IIP System designed, implemented and currently tested in the frame of the Polish national project entitled "Future Internet Engineering"1(in Polish "Inzynieria Internetu Przysz"- IIP). The IIP system uses virtualized network infrastructure that allows to set a number of, named, Parallel Internets essentially differing in solutions for the data and control planes. More precisely, we design three Parallel Internets: (1) IPv6 QoS that basically explores Diff Serv and NGN architectures and uses TCP/IP, (2) Content Aware Network (CAN) specially designed for efficient content delivery, and (3) Data Streams Switching (DSS) for handling constant rate traffic with strong QoS requirements. For the IIP System we design a novel network infrastructure, which is based on the virtualization of the network elements (links and nodes). Such approach is on the line with the expectations of the network infrastructure for the Future Internet. In the paper we mainly focus on the system architecture, Parallel Internets and some aspects of network virtualization.

In this article, we introduce a new space-division optical switching fabric architecture based on baseline switching networks. The new structure is built from optical switching elements (OSE) 2 × 2, 3 × 3, 2 × 3, and 3 × 2. The new structure is called the log2N-1 switching network and consists of fewer numbers of active and passive optical elements than traditional baseline switching networks composed of symmetrical OSEs. In the paper, we investigate space-division multiplane strict-sense and rearrangeable log2N-1 nonblocking switching networks and compare these with space-division multiplane baseline switching networks. The new structure has lower cost than other architectures for strict-sense nonblocking (SSNB) conditions and for rearrangeable (RNB) networks with odd number of stages. For RNB networks, when the number of stages is even, the cost of the multiplane log2N-1 optical switching network is equal to or higher than traditional networks.

The general case of multiplane wide-sense nonblocking multicast switching networks which are based on the baseline network are considered in this paper. Up to now, wide-sense nonblocking (WSNB) log2(N, 0, p), log2(N, m, p) and logd(N, 0, p) switching networks have been considered for multicast connections. A control algorithm under which these networks are WSNB is called the variable-size blocking window algorithm. In this paper, the path-searching algorithm is adopted for logd(N, m, p) networks with m extra stages and for general case d ¿ 2. The WSNB multicast conditions for logd(N, m, p) networks are presented (without proofs) and the optimal multicast switching networks are investigated.

In this paper, we propose the new architecture of the optical switching fabric which is based on the baseline switching network. Traditional baseline switching networks are composed of 2 × 2 (or d × d) switches. The new architecture considered in this paper is constructed from 2 × 2, 3 × 3, 2 × 3 and 3 × 2 switching elements. We show, that the proposed architecture requires less crosspoints than the traditional baseline architecture. We assumed an optical application, where semiconductor optical amplifiers are used as the optical switching elements. The proposed structure requires less number of active elements as well as passive optical splitters and combiners than the traditional baseline switching fabric. It also contains one stage fewer than the banyan network (therefore we called it the log2N - 1 switching fabric), which results in lower signal losses, distortions, and crosstalk.

The generalized multiplane wide-sense nonblocking switching network for multicast connections is presented in this paper. This switching network is based on the well-known baseline network. Up to now, wide-sense nonblocking operations for multicast connections have been considered for the following switching networks which are based on the baseline network: multiplane switching networks composed of 2 × 2 switching elements (called log2 (N, 0, p) networks), multiplane switching networks composed of 2 x 2 switching elements and with m extra stages (called log2 (N, m, p) networks), and multiplane generalized switching networks composed of d x d switching elements (called logd (N, 0, p) networks). The control algorithm under which these networks are wide-sense nonblocking for multicast connections is called the window algorithm. In this paper, multiplane switching networks composed of dxd switching elements with m extra stages (called logd (N, m, p) networks) are considered and in this way the last link in the studies of wide-sense nonblocking multicast multiplane switching networks under blocking window algorithms is presented. In this article, the path-searching algorithm is adopted for the general case d ? 2 and the wide-sense nonblocking conditions for switching networks for different sizes of the blocking window and for different numbers of extra stages are derived. The cost of different multiplane switching networks is compared in terms of the number of planes and the number of crosspoints.

A new control algorithm for log2(N, 0, p) switching networks composed of 2 x 2 switching elements has been proposed recently. Under this algorithm, log2(N,0,p) switching networks with even number of stages are wide-sense nonblocking (WSNB) if p is the same as for the rearrangeable nonblocking (RNB) one. The considerred algorithm and WSNB conditions did not take into account crosstalk constraint, which is an important factor in photonic switching. This paper enhanced this algorithm to the case when crosstalk in the switching fabric is not allowed. WSNB conditions for this enhanced algorithm are also derived. It is shown, that the number of planes required is less than those derived earlier in other papers for WSNB multiplane banyan- type switching fabrics under crosstalk constraint. Under this algorithm, log2( N,0,p) switching networks with odd number of stages and with zero crosstalk are WSNB if p is the same as for RNB one.

A new control algorithm for log2(N, 0,p) switching networks composed of 2 × 2 switching elements has been proposed. Under this algorithm, log2(N, 0,p) switching networks with even number of stages are wide-sense nonblocking (WSNB) ifpis the same as for the rearrangeable nonblocking (RNB) one. In this paper we extend this solution to logd(N, 0,p) switching networks. The control algorithm is appropriately modified to switching networks composed ofd×dswitches. Wide-sense nonblocking operation of such switching networks with even number of stages is proved. We showed that number of planes needed for WSNB operation is also the same as in RNB switching networks.

Wide-sense nonblocking (WSNB) log2(N, 0, p) switching networks under the fixed-size blocking window algorithm have been proposed by Tscha and Lee. We have generalized this approach to the variable-size blocking window algorithm and shown that the minimum number of planes depends on the window size and the number of stages. We have also generalized this concept to log2(N, m, p) switching networks. Later, Hwang and Lin have proved that for m > 2, the number of required planes for WSNB operation under the blocking window algorithm is always greater than for m les 2, and determined the optimal window size and optimal m. In this paper, we further generalized these results to logd(N, 0, p) switching networks. In the paper, we prove that the minimum number of planes for any d is reached also for different sizes of blocking window depending on d and n.

A new control algorithm for multi-plane banyantype switching fabrics has been proposed recently. It has been shown that using this algorithm such switching fabrics can be wide-sense nonblocking (WSNB) when the number of planes is lower than for the strictly nonblocking (SNB) one, and for even number of stages the WSNB switching fabric requires the same number of planes as rearrangeable one. The considered algorithm and WSNB conditions did not take into account crosstalk constraint, which is an important factor in photonic switching. This paper enhanced this algorithm to the case when the first order crosstalk in the switching fabric is not allowed. WSNB conditions for this enhanced algorithm are also derived. It is shown that the number of planes required is less than those derived earlier in other papers for WSNB multiplane banyantype switching fabrics under crosstalk constraint.

Recently, Hwang and Lin derived nonblocking conditions for multicast connections in Log/sub 2/(N,m,p) networks. They improved some conditions obtained earlier by Kabacin/spl acute/ski and Danilewicz. In this letter, we identify some inaccuracy in present results concerning wide-sense nonblocking Log/sub 2/(N,m,p) multicast networks, and give the correct results.

Performance evaluation of the MOQ switch recently proposed by us is discussed in this paper. In the MOQ switch both the switch fabric and buffers can operate at the same speed as input and output ports. This solution does not need any speedup in the switch fabric as well as any matching algorithms between inputs and outputs. The description and the first evaluation were presented earlier. In this paper new performance measures for the proposed MOQ switch are evaluated. The simulation studies have been carried out for switches of capacity 4/spl times/4, 8/spl times/8, 16/spl times/16 and 32/spl times/32, and under different traffic patterns. The simulations results are also compared with OQ switches and VOQ switches of the same sizes and under different scheduling algorithms: iSLIP, PIM, iRRM, MMRRS, HRRM.

In this paper, a new packet switch architecture with multiple output queuing (MOQ) is proposed. In this architecture, the nonblocking switch fabric, which has a capacity of N/spl times/N/sup 2/, and output buffers arranged into N separate queues for each output, are applied. Both switch fabric and buffers can operate at the same speed as input and output ports. This solution does not need any speedup in the switch fabric as well as arbitration logic for taking decisions which packets from inputs are to be transferred to outputs. The mean cell delay and cell loss probability, as performance measures for the proposed switch architecture, are evaluated and compared with the performance of the OQ architecture and VOQ architecture. The hardware complexity of the proposed switch is very similar to the VOQ switch but its performance is comparable to the OQ switch.

Multicast connections are used in broad-band switching networks as well as in parallel processing. We consider wide-sense and strict-sense nonblocking conditions for multi-log/sub 2/ N switching networks with multicast connections. We prove that such networks are wide-sense nonblocking if they are designed by vertically stacking at least t /spl middot/ 2/sup n-t-1/ + 2 /sup n-2t-1/ planes of a log/sub 2/ N networks together, where 1 /spl les/ t /spl les/ [n/2] and t defines the size of a blocking window K = 2/sup t/. For t = [n/2] and n even, and for [n/2] /spl les/ t /spl les/ n the number of planes must be at least t /spl middot/ 2/sup n-t-1/ + 1 and 2/sup t/ + (n - t - 1) /spl middot/ 2/sup n-t-1/ - 2/sup 2t-n-1/ + 1, respectively. In the case of strict-sense nonblocking switching networks, the number of planes is at least N/2. The results obtained in this paper show that in many cases number of planes in wide-sense nonblocking switching networks is less than those for t = [n/2] considered by Tscha and Lee (see ibid., vol.47, p.1425-31, Sept. 1999). The number of planes given in the paper is the minimum number of planes needed for wide-sense nonblocking operation provided that Algorithm 1 is used for setting up connections. The minimum number of planes for such operation in general is still open issue.

Non-blocking operation of log/sub 2/(N.m.p.) multicast switching networks is considered. A modified algorithm proposed Tscha and Lee (1992) and by Danilewicz and Kabacinski (see IEEE International Conference on Communications ICC 2000, New Orleans, LA, USA, p.1440-4, 2000) is used for setting up connections. Conditions under which log/sub 2/(N.m.p.) switching networks are non-blocking in the wide-sense are derived and proved. It is shown that wide-sense non-blocking log/sub 2/(N.m.p.) multicast switching networks require less vertically stacked copies of log/sub 2/(N.m.l.) networks and less 2/spl middot/2 switches than multi-log/sub 2/N networks considered by Danilewicz et al.

Non-blocking operation of multi-log/sub 2/N multicast switching network is considered. An algorithm used for setting up multicast connections is proposed and conditions under which multi-log/sub 2/N switching networks are non-blocking in the wide-sense are derived and proved. Both sufficiency and necessity are considered. It is shown that non-blocking multi-log/sub 2/N multicast switching networks require more vertically stacked copies of log/sub 2/N network than point-to-point networks. It is also shown that non-blocking-conditions given by Tscha and Lee (1992) constitute only a lower bound of non-blocking operation of such switching networks.