The hybrid vehicle to everything (V2X) network based on visible light communication (VLC) and radio frequency (RF) is an excellent choice for future vehicle communication. In this paper, the (user behavior)-based longitudinal-separation (LS) prediction model and the reverse-leadership strategy in the hybrid V2X network are firstly proposed. By user behavior , the LS is divided into active separation (ASP) and passive separation (PSP). By characteristics of ASP and PSP, the longitudinal-separation prediction model is constructed. By this model, ASP and PSP can be predicted respectively before they occur. By the prediction result of the model, a reverse-leadership strategy for the platoon is presented. By this strategy, communication links can be self-adaptively changed to avoid outages caused by LS. In this scheme (model＋strategy), LS can be predicted timely and communication links can be handed over in advance. Finally, the validity of the model and the effectiveness of the scheme are demonstrated by simulations based on data from NGSIM data set and PTV-Vissim simulation software. Besides, the proposed scheme not only has its comparative advantages of fewer outages and handovers , but also can decrease the path loss, average outage time and handover delay significantly.

Here, T g ‐minimised bandwidth‐allocated scheme is proposed for VPON supporting joint scheduling of multiple subsystems in metro‐access optical network. To minimise guard time (T g ) in WDM‐PON and TDM‐PON, the T g ‐transferred mechanism is introduced. To reduce the number of T g in OFDM‐PON, the subcarrier allocation algorithm based on the minimum number of T g is proposed. To effectively utilise the network bandwidth resources, the bandwidth allocation based on matrix model is established. To increase the utilisation of wavelength, a dynamic‐wavelength allocation mechanism is proposed. Finally, by the simulation, the effectiveness of T g ‐minimised bandwidth‐allocated scheme is demonstrated. Compared with other schemes, this scheme has at least 3% bandwidth utilisation improvement and lower average delay.

A passive optical network (PON) with multiple optical line terminals (OLTs) will play an important role in the optical access network. In this study, a novel dynamic bandwidth allocation (DBA) algorithm for the downstream channel in a multi‐OLT PON is proposed. To take care of bandwidth demands of different users, weight factors are introduced. Based on different weight factors, a core framework of the algorithm is constructed. Moreover, by combining a decision criterion and a bandwidth surplus ratio, a mathematical model of release bandwidth is established. Furthermore, by uniting judgement conditions and overload amount, a mathematical model of allocation bandwidth is also built. By constructing two mathematical models, the order and amount of release and allocation bandwidth are effectively solved. Moreover, to describe accurately the power of bandwidth transfer, a new concept ‘bandwidth‐transfer work’ is introduced. Based on the bandwidth‐transfer work, a ranking model is created to maximise the efficiency of the DBA. Finally, the effectiveness of the DBA algorithm and ranking model is demonstrated by the simulation and analysis.

In this study, mode transformation and united control mechanism for multiple subsystems in metro‐access optical network (MAON) are proposed to realise multi‐subsystem‐based virtual passive optical network. By combing the characteristics of multi‐point control protocols (MPCPs) of wavelength division multiplexing Ethernet passive optical network (WDM‐EPON) and orthogonal frequency division multiplexing passive optical network (OFDM‐PON), a unified MPCP (U‐MPCP) is proposed. Based on the U‐MPCP, flexible control node and central node are constructed to achieve asynchronous unified control of multiple subsystems. By designing new control frames, the mode transformation between two subsystems (WDM‐EPON and OFDM‐PON) can be carried out. It can not only finish the flexible transformation of optical network unit's (ONU's) working modes but also make the MAON have the backward compatibility to the existing access technologies. By creating transformation algorithm of ONU's working modes, the transmission delay of over‐load subsystem can be effectively reduced when ONU meets the condition of the mode transformation and finishes the transformation. Finally, by simulation, the effectiveness of the proposed scheme is demonstrated.

In the metro‐access optical network, bandwidth‐allocated mechanism and its algorithm are proposed for the multi‐subsystem‐based virtual passive optical network (VPON) that can implement the syncretism of multiple systems such as time division multiplexing‐PON, wavelength division multiplexing‐PON and orthogonal frequency division multiplexing‐PON. To avoid frequent bandwidth reallocation, the matrix of bandwidth‐demanded variation is introduced. According to the norm of this matrix, admission condition of bandwidth allocation for VPON users is established. To distinguish different bandwidth‐demanded variation of multiple subsystems and allocate bandwidth fairly and efficiently for VPON, the bandwidth‐allocated scheme is employed. To the increase of VPON's bandwidth demand, the multi‐granularity‐based bandwidth‐allocated algorithm is proposed to promote the admission probability of new VPONs. MATLAB is used to evaluate the performance of the proposed mechanism and algorithm. Considering the representativeness of various situations, the admission condition of bandwidth allocation for VPON users is demonstrated with ten VPONs. The bandwidth‐allocated scheme and algorithm are verified effectively in bandwidth‐utilised ratio with two original VPONs of high priority and two new VPONs of low priority, as well as in admission probability with four new VPONs.

Wavelength‐division multiplexing (WDM) technology has been recognised as one of the most promising solutions in optical access network. A general ring‐based multi‐wavelength optical access network based on WDM technology, which can realise triple‐play service including point‐to‐point service and multicast service is introduced in this study. To effectively utilise the network bandwidth resources, the authors propose a joint bandwidth allocation scheme on dedicated and shared wavelengths. The proposed scheme focuses on quality of services (QoSs) support. It is carried out according to the priority queue discipline to support QoS in terms of average packet delay, packet delay variance and throughput. Moreover, with the fair‐awareness in the scheduling scheme, the lower priority services can be prevented from starvation and the over‐allocation problem can be avoided. The simulation results show that the proposed scheme can reduce average packet delay and packet delay variance for high‐priority services to ensure QoS.

An efficient scheme of wavelength reuse is presented for solving the capacity limitation of WDM star single-hop networks by limited wavelengths. According to this scheme, the nodes supported by the network can be at least doubled under limited wavelength numbers. Under the same number of nodes, the delay of network can be greatly lowered, the throughput of the network can be increased 1–3 times, and the properties of the network can be efficiently improved.