Rerouting Technique Research Articles

Cross-layer TCP/IP segmentation, re-routing and adaptive modulation techniques to exploit instantaneous BER variations on parallel subchannels

This paper describes a cross-layer technique for TCP-enabled multichannel wireless communications systems such as Multiple-Input Multiple-Output (MIMO) links. The technique uses adaptive modulation (AM) and different packet re-routing strategies over physically decomposed sub-channels to exploit time-varying channel conditions. The paper will demonstrate that combining both AM and packet re-routing mechanisms can improve the overall performance of MIMO systems where sub-channels possess unbalanced or uneven time-varying error rate characteristics. A simulated wireless communications system is developed to evaluate packet re-routing techniques over four sub-channel connections made available to the link layer. It then considers the effect of cross-layer link modulation adaptation switching. The system is investigated primarily in terms of goodput for several channel arrangements and characteristics, for various data rates and mean bit error rates. Based on the investigation results, this paper will demonstrate that even simple re-routing and AM mechanisms may be beneficial for systems utilising multiple antennas, as long as these expose the underlying sub-channels and their different instantaneous error characteristics to the link layer.

Rerouting technique of the facial nerve in the procedure of removal of jugular foramen tumors: Outcomes and indications

But de la presentation To analyze retrospectively the functional outcome of the facial nerve after different nerve rerouting techniques in the procedure of removal of jugular foramen tumors, and to discuss their indications. Materiel et methodes From 2004 to 2013, 47 patients with jugular foramen tumor were operated on, in which 40 were totally, six near-totally and 1 partially resected. The pathologies consisted of 35 jugular paragangliomas, six schwannomas, 4 chordomas, one synovial sarcoma, and one ossifying myxoid tumor. According to the location and extension of the tumors, infra-temporal fossa type A (IFTA) approach was carried out in 23 cases, infra-temporal fossa combined translabyrinthine approach in 10 cases, petro-occipital trans-sigmoid approach (POTS) in 14 cases. The total rerouting of the facial nerve was done in 14 cases, partial rerouting in 12 cases, and no rerouting in 21 cases. Resultats These patients were followed up for 1-10 years. The facial nerve function after one year was HB I-II in 28 cases, HB III-IV in 17 cases, and HB V-VI in two cases. The facial nerve function after three years was HB I-II in 35 cases and HB III-IV in eight cases. The facial nerve function was deteriorated in 18 cases, improved in two cases, and unchanged in 27 cases. Conclusion The intraoperative facial nerve injury is a common complication in the surgery of jugular foramen tumors. The nature, size, location of tumors, preoperative facial function, surgical approach and intraoperative nerve management could affect the prognosis of facial nerve function. Partial or no rerouting of the facial nerve could be used in the procedure of removal of jugular foramen tumors in order to obtain better facial function. The tumors, those posterior and inferior to the labyrinth, could be removed via IFTA with partial or no rerouting of the facial nerve or POTS.

Rerouting Technique of the Facial Nerve in the Procedure of Removal of Jugular Foramen Tumors: Outcomes and Indications

But de la presentation To analyze retrospectively the functional outcome of the facial nerve after different nerve rerouting techniques in the procedure of removal of jugular foramen tumors, and to discuss their indications. Materiel et methodes From 2004 to 2013, 47 patients with jugular foramen tumor were operated on, in which 40 were totally, six near-totally and 1 partially resected. The pathologies consisted of 35 jugular paragangliomas, six schwannomas, 4 chordomas, one synovial sarcoma, and one ossifying myxoid tumor. According to the location and extension of the tumors, infra-temporal fossa type A (IFTA) approach was carried out in 23 cases, infra-temporal fossa combined translabyrinthine approach in 10 cases, petro-occipital trans-sigmoid approach (POTS) in 14 cases. The total rerouting of the facial nerve was done in 14 cases, partial rerouting in 12 cases, and no rerouting in 21 cases. Resultats These patients were followed up for 1-10 years. The facial nerve function after one year was HB I-II in 28 cases, HB III-IV in 17 cases, and HB V-VI in two cases. The facial nerve function after three years was HB I-II in 35 cases and HB III-IV in eight cases. The facial nerve function was deteriorated in 18 cases, improved in two cases, and unchanged in 27 cases. Conclusion The intraoperative facial nerve injury is a common complication in the surgery of jugular foramen tumors. The nature, size, location of tumors, preoperative facial function, surgical approach and intraoperative nerve management could affect the prognosis of facial nerve function. Partial or no rerouting of the facial nerve could be used in the procedure of removal of jugular foramen tumors in order to obtain better facial function. The tumors, those posterior and inferior to the labyrinth, could be removed via IFTA with partial or no rerouting of the facial nerve or POTS.

Towards fast rerouting-based energy efficient routing

The inefficiency of energy usage on the Internet has become a critical problem with its rapid growth, as all network devices operate at full capacity in spite of the real traffic load. Existing studies try to develop energy efficient routings by aggregating traffic and switching underutilized devices into sleep mode. However, most existing approaches do not address the problem of routing convergence well. Since traffic changes frequently in a network, routing convergence may be triggered frequently for an energy efficient routing, which may induce routing loops and black holes, resulting in severe packet loss. In this paper, we present a fast rerouting-based (FRR-based) energy efficient routing scheme, namely GreenFRR, which leverages the technique of fast rerouting to reduce the convergence time. We first study typical fast rerouting techniques and address the challenge of guaranteeing loop-free routing. Then, we formalize the FRR-based energy efficient routing problem and prove that the problem is NP-hard. In order to solve this problem, we design heuristic algorithms to maximize the number of sleeping links. In particular, we consider link utilization ratio and path stretch in our algorithms. We evaluate our scheme by simulations on real and synthetic topologies with real and synthetic traffic traces. The results show that the power consumed by line cards achieves a saving of 40% and the convergence time can be reduced by 95%.

Technique for rerouting without traffic disruption in optical networks

A novel lightpath rerouting technique is proposed, allowing data lossless rerouting without requiring additional optical transponders. Data lossless rerouting effectiveness is demonstrated considering a 112 Gbit/s polarisation multiplexed quadrature phase shift keying lightpath and coherent receiver.

Results of Anterior Facial Nerve Rerouting Procedures for Removing Skull Base Tumors

The purpose of this study was to estimate the rates of functional recovery of the facial nerve and of total tumor resection in patients who undergo short anterior rerouting and long anterior rerouting of the facial nerve in removal of skull base tumors. We retrospectively collected data on 37 patients with skull base tumors who underwent facial nerve rerouting during the procedure for tumor removal. Information on the rerouting technique, the completeness of tumor resection, and changes in facial nerve function were obtained from the medical records. Rerouting techniques were classified as short anterior rerouting or long anterior rerouting. Ten of 16 patients (62.5%) in the group with short anterior rerouting showed postoperative facial palsy, and all completely recovered within 1 year. In the group with long anterior rerouting, 18 of 21 patients (85.7%) showed postoperative facial palsy, and recovery to a preoperative level of facial function was found in 10 patients at 1 year of follow-up. Total tumor resection was possible in 94% and 81% of patients with short rerouting and long rerouting, respectively. The mean operation time was not significantly related to the postoperative recovery of facial function. Short rerouting techniques, when appropriately chosen on the basis of tumor and patient characteristics, offer excellent preservation of facial function and tumor resection, comparable to those of long rerouting techniques.

Fast ReRoute Technique in BGP with Secure Route Reliability Testing Algorithm

This paper deals with the Fast Reroute technique which is the extension of the Route Reliability Testing (RRT) algorithm. The main issues of the BGP are link failure and untrustworthiness of the link and many more. In a network when the actual link fails the data will not be sent to its destination and which results in congestion and also increases the load of the network. To deal with these issues, in this paper we propose a Fast ReRoute (FRR) Technique in BGP, which helps when the primary link fails by finding an alternate link for the data. The main advantage of this of this proposal is while finding the alternate link the lowest post failure, traffic load across all the links into the account and also it is possible to decrease the data packet loss. By simulation results, we show that the proposed rerouting technique reduces the packet loss and increases the throughput

A New Backup Topology Design Method for Congestion Avoidance in IP Fast Reroute

We present a backup topology design method to avoid congestion in IP Fast Reroute. IP Fast Reroute techniques prepare backup topologies used to determine backup routes after a network failure. However, using more backup topologies consumes a lot of network resources. Reducing the nu mber o f backup topologies is a problem, as some lin ks becomes overloaded. In this paper, we present a backup topology design method that splits the traffic on high load links to other links by considering network conditions, such as the traffic matrix or topology. The main idea of our method is the introduction of a concept called a Special Node, which is a node with a h igher node degree, in the backup topology. We quantitatively illustrate the effectiveness of our method in terms of maximu m lin k load reduction. The results show that, with the same nu mber of backup topologies as the conventional method, our method can reduce congestion by 75%. It is effective for various topology models and not dependent to the network size. In this paper, we demonstrate that by selecting about 20% of the nodes as Special Nodes is very effect ive, part icularly in large networks selecting Special Nodes whilst considering node position gives maximu m effect. In this paper, we present that using our approach of selecting Special Nodes in the backup topology and then maximize the number of available links to the Special Nodes we can avoid congestion in IP Fast Reroute.

Transfer Technique of an Anomalous Coronary Artery From the Anterior Pulmonary Artery

We describe a simple rerouting technique for an anteriorly situated anomalous left coronary artery from the pulmonary artery (ALCAPA), extending the left main coronary trunk with autologous aortic and pulmonary tissue. This technique is reproducible. It provides a tension-free aortocoronary anastomosis and a full potential for future growth.

Anastomosis of left to right superior vena cava for repair of Unroofed Coronary Sinus

Left superior vena cava (LSVC) draining into the left atrium is a rare congenital cardiac complex. It may appear as an isolated anomaly or as part of more complex cardiac anomalies. Intraatrial rerouting techniques have been the most common approaches to correcting LSVC drainage into the left atrium in patients without a connecting vein. Although these techniques have proved reliable and successful, there are cases in which extracardiac methods for managing this form of anomalous systemic drainage may be preferable. In the present report, we describe an extracardiac approach to the correction of LSVC draining into the left atrium.

Emergency re-routing of anterior sector venous outflow for right lobe living donor liver transplantation including the middle hepatic vein

Controversy remains over whether the middle hepatic vein should be included in the liver graft in right liver living donor liver transplantation. Congestion in the anterior sector of a right liver graft can cause graft malfunction, which is especially devastating in the case of a graft with marginal size in relation to recipient body size on top of poor pre-transplant recipient status. The case we report here highlighted the importance of the middle hepatic vein in right liver living donor liver transplantation. We illustrated the rectification of outflow obstruction of the middle hepatic vein in the anterior sector of right liver graft caused by technical error during transplantation. The rectification was performed with emergency re-routing using an artificial conduit. Congestion in the anterior sector of the graft improved immediately and the patient's postoperative liver function test results improved gradually. The middle hepatic vein is important for effective drainage of the anterior sector of a right liver graft. The re-routing technique described in the report can also be applied to cases in which the middle hepatic vein is injured during hepatectomy requiring immediate reconstruction.

Clinical Comparisons of the Anatomical Reconstruction and Modified Biceps Rerouting Technique for Chronic Posterolateral Instability Combined with Posterior Cruciate Ligament Reconstruction

The purpose of this study was to describe a one-stage operation for posterior cruciate ligament reconstruction with use of an Achilles tendon-bone allograft and a posterolateral corner reconstruction with use of two different methods, with a comparison of clinical outcomes in the two groups. Our study included forty-six patients who had undergone posterior cruciate ligament reconstruction with use of an Achilles tendon-bone allograft and posterolateral corner reconstruction with either anatomical reconstruction of the lateral collateral ligament and popliteus tendon with use of a tibialis posterior tendon allograft (twenty-one patients; Group A) or the modified biceps rerouting tenodesis (twenty-five patients; Group B) in an alternating fashion. Patients were assessed for knee instability with use of the dial test at 30° and 90°, together with varus and posterior stress radiography. At the two-year follow-up evaluation, although no significant difference was found on posterior stress radiography (mean and standard error, 5.7 ± 0.4 mm for Group A compared with 4.8 ± 0.4 mm for Group B), Group A showed more improvement than Group B on the dial test (16° ± 1° vs. 13° ± 1° at 30° and 17° ± 1° vs. 14° ± 1° at 90°; p = 0.001 for both) and varus stress radiography (3.6 ± 0.3 mm vs. 2.6 ± 0.3 mm; p = 0.024), in the Lysholm (29.5 ± 2.4 vs. 22.3 ± 2.3; p = 0.037) and the International Knee Documentation Committee knee scores (p = 0.041), and less terminal flexion loss (4.0° ± 1.2° vs. 8.8° ± 1.3°; p = 0.013). Combined with posterior cruciate ligament reconstruction, anatomical posterolateral corner reconstruction of the popliteus tendon and lateral collateral ligament showed better outcomes compared with the modified biceps rerouting tenodesis, although the mean differences of varus and external rotatory stability between the groups were relatively small. However, the overall difference might have been reduced by the negative value caused by overcorrection in Group B. This study demonstrated that anatomical posterolateral corner reconstruction is a reliable alternative method in addressing posterolateral corner and posterior cruciate ligament insufficiency of the knee, a finding that ideally should be tested in a randomized controlled trial.

Improved network resilience of wireless mesh networks using MPLS and Fast Re-Routing techniques

The performance of a wireless mesh network (WMN) can be significantly affected by node failures and medium-term time-varying phenomena in the wireless channel, which may lead to significant interruptions in packet delivery service. Because of their nature, WMNs are often deployed with an inherent degree of redundancy. In principle, this flexibility might be exploited to cope with the link failure problem by temporarily re-routing ongoing traffic on alternate paths. However, the existing routing protocols cannot be used for this purpose, since they either rely on link-state updates, which happen on a longer time scale than the phenomena under consideration, or the decisions are taken by the source node, which does not know the status on intermediate links. In this paper we present a Fast Re-Routing enabled architecture that is optimized for WMNs and allows nodes to react to local node or link failures by activating a pre-configured alternate path to reach a two-hop neighbor. The proposed scheme is enabled by label switching/stacking. Alternate paths are created automatically during the path setup phase via a lightweight protocol derived from LDP. The solution is proved to be effective through a testbed implementation.

Scalable Backup Configurations Creation for IP Fast Reroute

IP Fast Reroute techniques have been proposed to achieve fast failure recovery, just a few milliseconds. The basic idea of IP Fast Reroute is to reduce recovery time by precomputing backup routes. The multiple routing configurations (MRC) algorithm was proposed to implement IP Fast Reroute. MRC prepares backup configurations, which are used for finding a detour route after a failure. However, this algorithm establishes too many backup configurations to recover from failures. We propose a new backup configuration computation algorithm that creates the fewest possible configurations. The basic idea is to construct a spanning tree that excludes failure links in each backup configuration. We show that the effectiveness of our algorithm is especially high in large-scale power-law networks.

Preprocessing and Partial Rerouting Techniques for Accelerating Reconfiguration of Degradable VLSI Arrays

This paper presents novel techniques to accelerate the reconfiguration of degradable very large scale integration arrays. A preprocessing step is used to derive the upper and lower size bounds of the maximum logical array (MLA) such that only those subarrays that possibly contain the MLA are reconfigured, thereby reducing the reconfiguration time and also obtaining a same-sized logical array. In addition, the partial rerouting approach is generalized so that as many as possible previous routing results can be reused in the current rerouting step. The reconfiguration time is reduced from O((1-?)·s·m ·n) to its lower bound O((1-?)·m·n) for m × n host arrays with small fault density ?, where s is the expected routing length required per logical column.

Treating facial nerve palsy by true termino-lateral hypoglossal–facial nerve anastomosis

Hypoglossal-facial nerve anastomosis is a time-proven technique for the repair of facial nerve palsy. Efforts have been made to reduce hypoglossal nerve injury, the main drawback of the technique. In this study, the anastomosis is a true termino-lateral neurorrhaphy with only an epineural window in the hypoglossal nerve sheath. A re-routing technique of the temporal facial nerve is also performed to allow a direct anastomosis to the hypoglossal nerve without the need for a jump graft. The first three results reported are very encouraging, with a satisfactory return of facial mimics and without any impairment of lingual function.

Re-Routing at Critical Nodes to Enhance Performance of Wavelength Reassignment in All-Optical WDM Networks Without Wavelength Conversion

Reassignment of calls to different wavelengths on blocking can be used in WDM networks without wavelength conversion to get almost the same performance as that of WDM networks with wavelength conversion for circuit switched traffic . However, in a few networks, we did find that while the reassignment on blocking does improve the performance of WDM networks without wavelength conversion, the performance falls short of that of wavelength conversion networks. In this paper, we analyze the reasons for this behavior in these networks. On identifying certain critical nodes as a cause of this behavior, we propose a rerouting technique around the critical node. With a small amount of rerouting, this bottleneck can be removed and the performance of WDM networks without wavelength conversion becomes almost equal to that of networks with wavelength conversion, thus making the wavelength conversion (costly) feature, as redundant. In this paper, we also propose a technique to carry out seamless wavelength reassignment so as not to disrupt traffic during the wavelength reassignment process.

Systematic and efficient GMPLS-based recovery mechanism with soft-protection using enhanced LMP

generalized multi-protocol label switching (GMPLS-based) protection and restoration technologies will play significant role in next-generation broadband IP network to ensure the survivability. In this article, a systematic GMPLS-based recovery mechanism is proposed using enhanced link management protocol (LMP), which can support bidirectional fault notification relay more effectively. The major contributions and propositions in this article involve: 1) Soft-protection configuration for higher resource utilization with optimized routing; 2) Intelligent Shift from protection manner to restoration manner for the reduction of recovery latency; and 3) Toggleable revertive mode to increase restoration flexibility and to reduce loss of stability. Additionally, by leveraging valuable legacy including shared risk link group (SRLG) processing and fast reroute technique, the proposed recovery mechanism achieves higher resource utilization, fast and robust operation, satisfactory stability and flexibility, and is convenient in the application over heterogeneous transport networks.

Reconstruction by biceps tendon rerouting for posterolateral rotatory instability of the knee: Modification of the Clancy technique

We present a biceps rerouting technique for posterolateral rotatory instability using a modification of the biceps femoris tendon tenodesis of Clancy. The distinguishing features of this technique are the approach to the lateral femoral epicondyle through the interval between the iliotibial band and biceps femoris muscle, and fixation of the transferred biceps tendon at the isometric point. Reconstruction for posterolateral rotatory instability by modified biceps tendon rerouting can result in objectively and functionally acceptable knee function.Arthroscopy: The Journal of Arthroscopic and Related Surgery, Vol 17, No 6 (July-August), 2001: pp 664–667

Treatment of spastic thumb-in-palm deformity: A modified extensor pollicis longus tendon rerouting

Fourteen patients (15 hands) with spastic thumb-in-palm deformities were treated with a modified technique of extensor pollicis longus tendon rerouting. Twelve patients obtained satisfactory correction of their deformities. Although functional improvement was not always anticipated, it was achieved to some degree in 12 patients. Extensor pollicis longus tendon rerouting can provide satisfactory correction of severe thumb-in-palm deformity especially when combined with other procedures such as metacarpophalangeal joint arthrodesis and thumb intrinsic muscle release. The modified rerouting technique can be done with a single incision and allows easy adjustment of tension.