阅读说明：本技术 一种5g异种网络间基于时间门限的优先级垂直切换方法 (Priority vertical switching method based on time threshold between 5G heterogeneous networks ) 是由 蔡家麟 于 2021-09-28 设计创作，主要内容包括：本发明公开了一种5G异种网络间基于时间门限的优先级垂直切换方法,该方法以5G网络在无线资源管理方面采用的CoMP技术为基础,针对5G异种网络应用环境提出一种改进基于时间门限的优先级跳变垂直切换的方法。该方法通过改进异种网络间双重覆盖区内在线语音呼叫的DVH决策算法以减轻蜂窝覆盖区内信道占用的拥塞程度。本发明具有在保持系统整体高信道利用率的同时,明显改善系统优先级UVH呼叫丢失率、非优先级UVH呼叫丢失率和新增蜂窝呼叫阻塞率性能,实现网络信道资源有效利用的有益效果。(The invention discloses a time threshold-based priority vertical switching method among 5G heterogeneous networks, which is based on a CoMP technology adopted by the 5G network in the aspect of wireless resource management and aims at providing a method for improving time threshold-based priority jump vertical switching aiming at a 5G heterogeneous network application environment. The method reduces the congestion degree of channel occupation in a cellular coverage area by improving a DVH decision algorithm of online voice calls in a dual coverage area among heterogeneous networks. The invention has the advantages of obviously improving the performances of UVH call loss rate of system priority, UVH call loss rate of non-priority and call blocking rate of newly-added honeycomb while keeping the integral high channel utilization rate of the system, and realizing the effective utilization of network channel resources.)

1. A priority vertical switching method based on time threshold between 5G heterogeneous networks, wherein the 5G heterogeneous networks refer to a space between a cellular mobile network and a wireless local area network based on 5G wireless technology, the method is characterized by comprising the following steps:

a) online voice and broadband data call classification

The method comprises the steps that online communication time of a call is monitored, a voice and broadband data time threshold is set according to the tolerance of a user to call drop, the voice time threshold is a time set value which is larger than the minimum call duration time acceptable by a voice user, and the broadband data time threshold is a time set value which is smaller than the maximum online data transmission time which can be tolerated by a broadband data user to drop, so that online voice and broadband data calls in a cellular coverage area are classified according to priority; online voice calls less than a voice time threshold and online broadband data calls greater than a broadband data time threshold are referred to as priority calls, while online voice calls greater than or equal to the voice time threshold and online broadband data calls less than or equal to the broadband data time threshold are referred to as non-priority calls;

b) priority algorithm for calling occupation and channel preemption in 5G heterogeneous network cellular coverage area

Aiming at UVH (namely uplink vertical handover call and newly added cellular call) with cellular mobile channel occupation and preemption requirements in a cellular coverage area of a 5G heterogeneous network, the priority of uplink vertical handover and the tolerance of a user to the dropped handover call are comprehensively considered, and a priority algorithm for designing the call occupation and channel preemption is as follows: when an idle cellular mobile channel exists in a cellular coverage area, the priority UVH call, the non-priority UVH call and the newly added cellular call have the same priority for occupying the channel; when no idle cellular mobile channel exists in the cellular coverage area and the preemptible cellular channel in the dual coverage range of the 5G cellular network and the wireless local area network needs to be preempted through competition, the preemption priority of the non-priority UVH call and the newly added cellular call is reduced to be lower than the priority level of the priority UVH call, namely, the priority UVH call has stronger channel preemption capability compared with the non-priority UVH call and the newly added cellular call;

c) decision algorithm for online voice call DVH (digital video disk) in dual coverage area of 5G heterogeneous network, namely downlink vertical handover

As long as the WLAN in the 5G dual coverage area has an idle wireless channel, the online voice call entering the dual coverage area, including the priority voice call and the non-priority voice call, should perform the DVH procedure, i.e., the call directly abandons the cellular mobile channel to occupy the WLAN wireless channel, but if no idle WLAN wireless channel exists at this time, the online voice call entering the dual coverage area, including the priority voice call and the non-priority voice call, is allowed to temporarily continue occupying the cellular mobile channel under the condition that no cellular mobile channel is preempted, so as to avoid increasing unnecessary online voice drop;

d) cellular mobile channel allocation in a 5G heterogeneous network cellular coverage area

The total channel capacity of the cell in the 5G heterogeneous network is B basic bandwidth units, B^uChannel threshold, B, for allowing occupation of cellular mobile channels for priority UVH callsⁿChannel threshold values for cellular mobile channels allowed to be occupied for non-priority UVH calls and new cellular calls, where B^uAnd BⁿOnly a label different from B; if the number of channels occupied by the cell is less than B^uIn basic bandwidth unit, the priority UVH calls to directly complete the uplink vertical switch and occupy the cellular mobile channel; if the number of channels occupied by the cell is less than BⁿThe basic bandwidth unit, the non-priority UVH call and the new cell call can occupy the cell mobile channel; defining channel threshold B, B^uAnd BⁿSatisfies the relation: b ═ B^u＝Bⁿ。

Technical Field

The invention relates to the technical field of wireless communication, in particular to a priority vertical switching method based on a time threshold among 5G heterogeneous networks.

Background

Currently, with the increasing demand of people for mobile access services, 5G wireless communication technology is developing towards the direction of implementing heterogeneous wireless network interworking. Cellular mobile networks and Wireless Local Area Networks (WLANs) are two major wireless communication networks in modern wireless communications. Cellular mobile networks are characterized by large coverage and low bandwidth, while WLANs are characterized by small coverage and high bandwidth. The interworking between the cellular mobile network and the WLAN can complement the advantages of the cellular mobile network and the WLAN, thereby enhancing the quality of service (QoS) of the provided service.

The process of switching connections between networks is called handover. Handovers between the same access technology networks (e.g., between WLANs) are referred to as horizontal handovers, while handovers between different access technology networks (e.g., cellular mobile networks and WLANs) are referred to as vertical handovers. Vertical handovers may be further divided into Downstream Vertical Handovers (DVHs) and Upstream Vertical Handovers (UVH). For a cellular mobile network and WLAN interworking system, DVH refers to vertical handoff from the cellular mobile network to the WLAN, and UVH refers to vertical handoff from the WLAN to the cellular mobile network. DVH is the handover procedure of the mobile user from low bandwidth large coverage to high bandwidth limited coverage network, and UVH is the handover procedure of the mobile user from high bandwidth limited coverage to low bandwidth large coverage network.

Vertical handover between heterogeneous networks is a significant challenge for seamless mobility in a new generation of mobile networks. In recent years, many handover methods for vertical handover of heterogeneous wireless networks have appeared, but these methods rarely involve vertical handover for channel preemption. T. L.Sheu et al in 2010 in the publication of "Wireless Networks" journal, "A channel prediction model for vertical handoff in a WLAN-embedded cellular network, propose a channel preemption vertical switching method (PMV method for short) suitable for the interworking between cellular mobile network and WLAN, the core idea is: if all the effective mobile channels in the cellular mobile network are occupied, only new calls in the coverage area of the single cellular mobile network or handover calls which execute UVH procedure to handover to the coverage area of the single cellular mobile network can preempt the existing cellular mobile channels in the dual coverage areas of the cellular mobile network and the WLAN. The preempted online cellular call is forced to perform a DVH procedure with a downlink vertical handoff from the cellular mobile network to the WLAN. The PMV method effectively reduces the rate of new call blocking and UVH handover call loss in the cellular mobile network. The processing method of the handover call will directly affect the quality of service (QoS) for providing services to the Mobile users and the performance of the interworking system, i.katzela and m.naghshineh, as early as 1996, indicated in the paper "Channel Assignment Schemes for Cellular Mobile telecommunications Systems" published in the "IEEE Personal Communications" journal: "loss of handover calls should be avoided more than blocking of new calls within the cellular mobile network". However, in the design of how to perform cellular mobile channel occupation and preemption for the newly added call in a single-cell coverage area and the vertical handover call performing UVH handover to the single-cell coverage area, the PMV method does not consider the sequence of the two, but gives UVH handover call the same competition and right to preempt the cellular mobile channel as the newly added call, and as a result, the call loss rate performance of UVH handover call cannot be further improved. Aiming at the defects of the PMV method, An article "An uplink Priority Channel prediction Scheme for Vertical Handoff in Cellular/WLAN Interworking" proposes An uplink Priority Vertical Handoff method (referred to as UPPS method for short) suitable for a Cellular mobile network and a WLAN Interworking network in 2011 'IEEE WICOM' international conference. The method effectively improves UVH handover call drop rate performance by increasing UVH the priority of handover calls in uplink vertical handovers with channel preemption, but thereby also increases somewhat its newly added cellular call blocking rate. For limited cellular mobile channel resources, UVH handover call loss rate and newly added cellular call blocking rate are contradictory, and biasing either one will degrade the performance of the other. How to achieve the best balance between the two is always the focus of attention in the wireless communication field. Salamah et al, 2005, in "New Trends in Computer Networks", journal published by "A Fair Bandwidth Allocation Scheme for Multimedia Handoff Calls in Cellular Networks", states: for the online voice call, if the call duration is short, the call drops, the user is very irritated, and when the call drops after a certain duration, the discontent emotion of the user is not strong; also, for online data calls, a user may generally tolerate dropping when the connection time is less than an acceptable range, but the dissatisfaction of the user will be quite intense when the online data transmission has been on for a significant period of time. Thus, m.salamah et al, in the above-mentioned paper, proposed a time-threshold channel allocation method (TTS method for short) for horizontal handover in cellular networks. The method carries out priority classification on the on-line horizontal switching call by monitoring the on-line communication time of the horizontal switching call and according to different tolerances of users to voice and data services, and aims to improve the blocking rate performance of a newly added call while ensuring that the priority horizontal switching call of a time sensitive user has lower loss rate. In IEEE WICOM' 2012 international conference, the article "a Time-threshold-based uplink Priority Scheme for Vertical Handoff in Cellular/WLAN Interworking" applies the Time threshold thought of horizontal Handoff of m.salamah et al for the same network to Vertical Handoff between heterogeneous networks, and proposes a Time-threshold-based uplink Vertical Handoff method (TUPS method for short) between heterogeneous networks, which has the advantages of maintaining the utilization rate of a system high Cellular mobile channel and lower Time-sensitive user uplink Vertical Handoff call loss rate performance, and obviously improving the newly added Cellular call blocking rate performance in the UPPS method. On the basis, an uplink Priority Vertical switching method (TPHS method for short) suitable for a Cellular mobile network and a WLAN Interworking network is proposed in a paper 'A Time-threshold-based Priority hosting Scheme for Vertical Handoff in Cellular/WLAN Interworking' published in an international conference of 'IEEE Computer and Communications' in 2017. The method provides a priority jump algorithm aiming at the call occupation and channel preemption in the cellular coverage area on the basis of a vertical switching method based on a time threshold so as to adjust the capacity of various calls for competing for cellular mobile channels in different environments, and simultaneously, the congestion degree of the channels in the cellular coverage area is reduced by designing a DVH decision algorithm of online voice calls in a double coverage area. Nevertheless, how to further improve UVH call drop rate and new cellular call blocking rate performance is still an important goal of research. As the 5G network adopts the CoMP (coordinated multi-point transmission) technology in the aspect of wireless resource management, namely, the coordinated shared channel state information and scheduling useful information among multiple base stations are adopted in the coverage edge area of the base stations, the interference is effectively reduced through the combined processing and sending of the information among the coordinated base stations, and the possibility of packet data loss caused by the execution of a switching process under the condition that idle switching channels exist among heterogeneous networks is greatly reduced. Therefore, in the conventional vertical handover algorithm between heterogeneous networks, the method for allowing the mobile terminal to stay in the cellular coverage area, which is designed for considering that voice data loss is possibly caused by the time-sensitive online voice call execution DVH process, can be modified so as to achieve the purpose of further improving the channel congestion degree of the cellular coverage area of the 5G network.

Disclosure of Invention

The invention aims to provide a time threshold-based priority vertical switching method between 5G heterogeneous networks, aiming at the defects of the prior art, and providing a method for improving time threshold-based priority jump vertical switching aiming at the application environment of the 5G heterogeneous networks on the basis of a CoMP technology adopted by the 5G heterogeneous networks in the aspect of wireless resource management. The method reduces the congestion degree of channel occupation in a cellular coverage area by improving a DVH decision algorithm of online voice calls in a dual coverage area among heterogeneous networks. The invention has the advantages of obviously improving the performances of UVH call loss rate of system priority, UVH call loss rate of non-priority and call blocking rate of newly-added honeycomb while keeping the integral high channel utilization rate of the system, and realizing the effective utilization of network channel resources.

The specific technical scheme for realizing the purpose of the invention is as follows:

a priority vertical switching method based on time threshold between 5G heterogeneous networks, wherein the 5G heterogeneous networks refer to a space between a cellular mobile network and a wireless local area network based on 5G wireless technology, the method comprises the following steps:

a) online voice and broadband data call classification

The method comprises the steps that online communication time of a call is monitored, a voice and broadband data time threshold is set according to the tolerance of a user to call drop, the voice time threshold is a time set value which is larger than the minimum call duration time acceptable by a voice user, and the broadband data time threshold is a time set value which is smaller than the maximum online data transmission time which can be tolerated by a broadband data user to drop, so that online voice and broadband data calls in a cellular coverage area are classified according to priority; online voice calls less than a voice time threshold and online broadband data calls greater than a broadband data time threshold are referred to as priority calls, while online voice calls greater than or equal to the voice time threshold and online broadband data calls less than or equal to the broadband data time threshold are referred to as non-priority calls;

b) priority algorithm for calling occupation and channel preemption in 5G heterogeneous network cellular coverage area

Aiming at UVH handover calls and newly added cellular calls with cellular mobile channel occupation and preemption requirements in a cellular coverage area of a 5G heterogeneous network, the priority of uplink vertical handover and the tolerance of a user to the call handover drop are comprehensively considered, and a priority algorithm for designing the call occupation and channel preemption is as follows: when an idle cellular mobile channel exists in a cellular coverage area, the priority UVH call, the non-priority UVH call and the newly added cellular call have the same priority for occupying the channel; when no idle cellular mobile channel exists in the cellular coverage area and the preemptible cellular channel in the dual coverage range of the 5G cellular network and the wireless local area network needs to be preempted through competition, the preemption priority of the non-priority UVH call and the newly added cellular call is reduced to be lower than the priority level of the priority UVH call, namely, the priority UVH call has stronger channel preemption capability compared with the non-priority UVH call and the newly added cellular call;

c) DVH decision algorithm for online voice call in 5G heterogeneous network dual coverage area

Whenever there is an idle wireless channel in the WLAN in the 5G dual coverage area, the online voice call entering the dual coverage area, including the priority voice call and the non-priority voice call, should perform the DVH procedure, i.e. the call directly abandons the cellular mobile channel to occupy the WLAN wireless channel, but if there is no idle WLAN wireless channel, the online voice call entering the dual coverage area, including the priority voice call and the non-priority voice call, is allowed to temporarily continue occupying the cellular mobile channel under the condition that no cellular mobile channel is preempted, so as to avoid unnecessary online voice drop

d) Cellular mobile channel allocation in a 5G heterogeneous network cellular coverage area

The total channel capacity of the cell in the 5G heterogeneous network is B basic bandwidth units, B^uChannel threshold, B, for allowing occupation of cellular mobile channels for priority UVH callsⁿChannel threshold values for cellular mobile channels allowed to be occupied for non-priority UVH calls and new cellular calls, where B^uAnd BⁿOnly a label different from B; if the number of channels occupied by the cell is less than B^uIn basic bandwidth unit, the priority UVH calls to directly complete the uplink vertical switch and occupy the cellular mobile channel; if the number of channels occupied by the cell is less than BⁿThe basic bandwidth unit, the non-priority UVH call and the new cell call can occupy the cell mobile channel; defining channel threshold B, B in the present invention^uAnd BⁿSatisfies the relation: b ═ B^u＝Bⁿ。

The interworking system of the present invention has three types of cellular mobile channels: an idle cellular channel, a preemptible cellular channel and a non-preemptive cellular channel. Wherein, the preemptible cellular channel is a cellular channel occupied by a call in a dual coverage area; a non-preemptive cellular channel refers to a cellular channel occupied by a call in a single cellular mobile coverage area.

In the interworking system between the 5G cellular mobile network and the WLAN, the online broadband data call entering the dual coverage area should perform the DVH procedure as much as possible, i.e. as long as there is a free WLAN radio channel, the call abandons the cellular mobile channel and instead occupies the WLAN radio channel. However, if there is no idle WLAN radio channel, the online broadband data call entering the dual coverage area is allowed to temporarily continue occupying the cellular mobile channel even without the occurrence of the cellular mobile channel preemption, so as to avoid adding unnecessary online broadband data drops.

The invention has obvious advantages for improving the performances of the call loss rate of the switching of the priority UVH, the call loss rate of the switching of the non-priority UVH and the call blocking rate of the newly added cellular in the process of executing the uplink vertical switching based on the 5G heterogeneous network environment.

Drawings

FIG. 1 is a block diagram of a cellular mobile network and WLAN interworking system;

FIG. 2 is a simulation graph of a relationship between a call loss rate of a priority uplink vertical handover and a cellular load;

FIG. 3 is a simulation graph of the relationship between the call loss rate of non-priority uplink vertical handover and the cellular load;

FIG. 4 is a graph showing a simulation of a call blocking rate versus cell load for a newly added cell;

FIG. 5 is a graph of a simulation of cellular mobile channel utilization versus cellular load;

fig. 6 is a simulation graph of WLAN radio channel utilization versus cellular load.

Detailed Description

The invention is explained in more detail below with reference to the figures and examples. The following examples are not intended to limit the invention. Variations and advantages that may occur to those skilled in the art may be incorporated into the invention without departing from the spirit and scope of the inventive concept.

Fig. 1 shows a cellular mobile network/WLAN interworking system architecture, in which: single cell coverage 1, vertical handover 2 and dual coverage 3; the architecture provides voice and broadband data services to cellular mobile terminals and wireless terminals within the coverage area of the WLAN. In the embodiment simulation, the channel capacity B of each cell is 20BBUs (basic bandwidth unit), and the channel capacity of each WLAN coverage area is 54 BBUs. Channel threshold B set by cellular mobile channel^uAnd BⁿAre all 20 BBUs. To meet the QoS requirements of the service, a single voice call needs to occupy one basic bandwidth unit channel, while a single broadband data call needs to occupy two basic bandwidth unit channels. The process of generating new calls in the cell follows the Poisson process with the mean value λ c, while the process of generating new calls in the coverage area of the WLAN follows the Poisson process with the mean value λ w (where λ w is 0.04call/s), and the performance indexes of call blocking rate and loss rate related to the present invention are mainly affected by the λ c change. The communication duration of each call follows a negative exponential distribution with an average of 6 minutes. The stay times of the online calling subscriber within a single cell and a single WLAN coverage area follow negative exponential distributions with mean values of 2 minutes and 4 minutes, respectively. ForThe voice and broadband data time thresholds for prioritized and non-prioritized UVH calls are 120 seconds and 30 seconds, respectively.

Fig. 2, 3 and 4 show graphs simulating the relationship between the call loss rate of priority UVH, the call loss rate of non-priority UVH and the call blocking rate of newly added cells and the cell load, respectively. In fig. 2: the abscissa is the cellular call arrival rate; the ordinate is the priority UVH call loss rate; curve A is the invention, B is TPHS; in fig. 3: the abscissa is the cellular call arrival rate; the ordinate is the non-priority UVH call loss rate; curve A is the invention, B is TPHS; in fig. 4: the abscissa is the cellular call arrival rate; the ordinate is the newly added cellular call blocking rate; curve A is the invention and curve B is TPHS. According to the simulation result, the following results are obtained: compared with the TPHS method, the priority vertical switching method based on the time threshold between the heterogeneous networks based on the 5G wireless technology obviously improves the call loss rate of UVH call of the system priority, the call loss rate of UVH call of non-priority and the blocking rate performance of newly added cellular calls while keeping the high channel utilization rate of the whole system. This is because the DVH decision algorithm for the online voice calls in the dual coverage area is improved, so that a large number of online voice calls which are originally dropped due to the concern of executing the handover process can directly occupy the idle WLAN wireless channel through the DVH vertical handover process, thereby greatly reducing the congestion degree of the cellular mobile channel in the cellular coverage area under heavy load conditions. As can be seen from fig. 2: when the average arrival rate lambdac of newly added calls of a cellular cell reaches 0.08call/s of heavier load, the call loss rates of the priority UVH of the method and the TPHS method are respectively 2.50E-3 and 7.20E-3, and the improvement degree of the method on the call loss rate of the priority UVH reaches 65.28 percent compared with the TPHS method; also, in fig. 3 at this time: the non-priority UVH call loss rates of the method and the TPHS method are respectively 1.30E-2 and 2.20E-2, and the improvement degree of the method on the non-priority UVH call loss rate is 40.91% compared with the TPHS method; again, as can be further seen in fig. 4: when the average arrival rate lambdac of the newly added call of the cellular cell is also 0.08call/s, the blocking rates of the newly added cellular call of the method and the TPHS method are respectively 3.60E-2 and 6.40E-2, and compared with the TPHS method, the method has the advantages that the improvement degree of the blocking rate of the newly added cellular call reaches 43.75 percent, and the improvement effect is quite obvious. Fig. 5 and 6 show graphs simulating cellular mobile channel utilization and WLAN radio channel utilization versus cellular load. In fig. 5: the abscissa is the cellular call arrival rate; the ordinate is the cellular mobile channel utilization; curve A is the invention, B is TPHS; in fig. 6: the abscissa is the cellular call arrival rate; the ordinate is the utilization rate of the WLAN wireless channel; curve A is the invention and curve B is TPHS. Although fig. 5 shows that the cellular mobile channel utilization is reduced by the inventive method compared to the TPHS method, it is just the object of the inventive method. Under the condition of not influencing the voice communication quality, the method enables a large number of online voice calls in a dual coverage area to execute a DVH process to occupy WLAN wireless channels with relatively abundant channel resources, so that the distribution pressure of cellular mobile channels in a cellular coverage area is greatly reduced, more calls in a single cellular coverage area can be accommodated, and once the calls cannot obtain the cellular mobile channels, the calls are directly in danger of being disconnected. Therefore, the overall channel utilization of the system is not reduced, and only a part of the channel utilization is transferred from the 5G cellular mobile network to the WLAN network, i.e. the WLAN network shares part of the load.

Therefore, the analysis of the figures and the examples proves that: the time threshold priority vertical switching method based on the 5G wireless technology provided by the invention obviously improves the UVH call loss rate of the system priority, the UVH call loss rate of the non-priority and the congestion rate performance of newly added cellular calls while keeping the whole channel utilization rate of the system, and realizes the beneficial effect of effectively utilizing channel resources.