You are presented with multiple paper abstracts, alongside the associated literature review and chapter titles. Given the provided information, you are going to do a literature review. Please generate a coherent literature review that synthesizes the content, draws connections between different works, highlights major findings, and identifies any gaps in the existing research.

Literature Review Title: A Literature Survey on Handoff for Mobile IPv6 
Chapter Title:  VI. THE MECHANISM BASED ON MPLS AND FLOW LABEL 
1. Abstract of Cited Paper (BIB001):  The triangle routing problem is one of the most important study issues in the Mobile IP environment. Generally speaking, it always introduces a lot of routing overhead when the packets are delivered in triangle path due to the processing of arrival packets at the home agent. In this paper the multi-protocol label switching (MPLS) technology is considered as the transport for the support of Mobile IP The dynamic label switch paths (LSP), with dynamic label binding, are applied for the path construction of the mobile node during its movement. And the concept of traffic driven is applied for the establishment and release of the dynamic LSP. The experimental results illustrate that as the inter packet arrival time is getting longer then more labels are required at the switch routers if we want to increase the percentage of packets delivered in cut-through so that the packet delay time can be limited. And, for the allocation of labels, the number of dynamic labels required at the edge label switch router (LSR) connected with the home agent and the LSR within the critical path shall be about 2 times of which of the other LSR in order to maintain the desired transmission performance. In additional, the effects of the threshold values selected for the control of dynamic LSP are also studied in this paper. 
2. Abstract of Cited Paper (BIB002):  In this paper, we propose an architecture for the MPLS (Multi-Protocol Label Switching)-based micro-mobility management including label switched path setup, packet forwarding, handoff processing, and paging. In order to prevent packet loss during handoff, we propose two packet recovery mechanisms, namely: buffer time-based packet recovery and medium access control (MAC) layer assisted packet recovery schemes. Simulation results show that the MAC layer assisted packet recuvery scheme has a better performance than buffer time-based scheme. Our proposed scheme provides a higher throughput when compared with other IP micro-mobility protocols including Cellular IP, HAWAII, and Hierarchical Mobile IP. 
3. Abstract of Cited Paper (BIB003):  In next generation wireless networks, mobile nodes will be equipped with multiple interfaces and will be able to take advantage of overlay networks. In such environment, global IP mobility solutions have to be optimized to handle micro-mobility management, where low-latency handoffs are essential. Signalling overhead, foreign network detection and reconfiguration are not always met in current solutions. In this paper, we propose a new solution to overcome these limitations, namely a layer 2.5 mobility scheme for fast handover based on MPLS forwarding mechanism and a virtual interface architecture: W-MPLS. Our MPLS approach, is triggered by the mobile and controlled by the network. It gives the ability to provide QoS through traffic engineering, and scales well to fulfil fast handover performance. Based on the proposed architecture, we also present a location update optimization method. 
4. Abstract of Cited Paper (BIB004):  A Realization of mobile All-IP networks calls not only for seamless handover protocols, but also fast processing, especially for real-time IP traffic flows. In this paper, we propose to exploit pre-established label switched paths with the aim to reduce handover processing latency which is one of the most critical performance metrics in micro-mobility environment. Thus, our proposed scheme has an advantage of offering micro-mobility to Mobile IP (MIP) with lower-latency handover as compared with the several existing MPLS-based MIP approaches. A detailed analytic model of setting up LSPs for fast handover processing is presented. Further, we do not only investigate the performance of our model but also propose detailed signaling steps so that our proposed scheme could be run on MPLS-based MIP system.

Literature Review:
This method has two switching strategy: the integration of MPLS and Mobile IP, insert flow label to Mobile IP. The previous one takes advantage of MPLS, it does not need tunnel package, and it improves the performance of switch by using MPLS label to achieve fast switch. The latter one uses the flow label mechanism to realize redirection of data packet and reduce the data loss. Recently, with more and more ISP and users moving to the MPLS network, many suggestions on the integration of MPLS and Mobile IP are proposed, such as  , [14] , BIB002 , BIB003 , the integration plan does not need the tunnel to transfer the data, instead, it takes advantage of the fact that search the label takes less time than search IP address, to reduce the network burden and improve the switching performance. Micro-mobile plan for MPLS is proposed by people, such as BIB005 ,  ,  , BIB001 ,  . At present, many improvements have been made to this plan, a 2 5 mobility scheme for fast handover based on MPLS forwarding mechanism and a virtual interface architecture (W-MPLS) is detailed and discussion as follows BIB004 . In addition, in order to achieve seamlessly switching, the seamless switching scheme of Mobile IPv6 network relying on MPLS networks is proposed  , the scheme accomplishes switching of low delay and grouping loss by limiting reconstructed domain of label switched path (LSP) and dual broadcasting data for host during switching, meanwhile an algorithm that we can fast find the nearest public point, through which group data is delivered, before and after host switched is employed to minimize delay of LSP reconstructing and redundancy of dual broadcasting. For the existing scheme of combining multi protocol label switching (MPLS) and IPv6, there have been some problems like how restoration of label switching path without mistake is established, so Predictive fast switching IPv6 base on MPLS arises  , the scheme may minimize switching delay by defining forecast information table and algorithm of predictive MPLS transmitting and switching, furthermore by improving LSP topology construction and adopting dual broadcasting mechanism, data packets loss rate reduce effectively and ability of error recovery improves. W-MPLS structure shows in Figure 7 , RG(Root Gate) / FA is the root gateway of MPLS domain (i.e. FA); LER(Label Edge Router) is the labeling boundary router, connecting MN as first hop access router and responsible for label insertion between the data packet link road layer and network layer; LSR(Label Switch Router) is the label switching router, forwarding data depending on MPLS labels, most routers in network support MPLS protocol, LSP (label Switched Path) among FA, MN, CN and HA all transmit messages by looking for tag, instead of IP, using MPLS routers and switches that are both established ahead according to label distributing protocol, by this means higher speed can be obtained than that in which every router searches IP address in router transmitting table. The basic design concept of MPLS is that, when MN accesses router in turn, as shown in the graph, when A-LEAR1 is switched to A-LEAR2, binding registration messages are sent to new A-LER2 from MN, and then A-LER2 finally transmits the messages to FA by established LSP ahead, FA updates binding information from MN. A-LER2 at the same time notifies the front access router A-LER1 new care-of address of the MN, thereby A-LER1 transmits the data packets sent to MN packets to the new care-of address. In order to reduce the load on the RG and switching latency, optimization solution has been raised in this article that enhanced mobile LSR (i.e. ME-LSR) is introduced between MN and RG. When MN switches from the pre-network to the new network, from A-LER1 to A-LER2 as shown in the graph, ME-LSR1 receives the registration messages from MN, updates them to MN binding information table, establishes LSP about MN with new access router A-LER2 and then deserts the registration messages, not to forward them to FA/RG. ME-LSR1 intercepts the data packets and the new care-of address sent to MN. W-MPLS method makes use of MPLS label to forward data, instead of finding IP addresses, and it no longer needs to forward data by tunnel like Mobile IP, thereby speeds up the rate and effectively reduces forwarding delay. In the signal load aspects, MN does not need to deliver binding update request frequently to the distant FA and HA, which dramatically reduces signal load compared with MIPv6. Simultaneously due that the header of MPLS is smaller than that of IP and that W-MPLS does not require tunnels to forward data, thereby such characters reduce load of router and network; in the implementation complexity aspects, the scheme requests router to support MPLS, which increases entities of ME-LSR, thereby more complex than MIPv6 in designing.