A heterogeneous network time-limited non-real-time data avoidance vertical handover method

Abstract

The application discloses a heterogeneous network time limit-based non-real-time data avoidance vertical switching method, which is an improved time limit-based non-real-time data variable-speed vertical switching method based on the fact that non-real-time online broadband data calls have non-sensitivity to time and various coverage area variable-speed transmission has greatly improved transmission efficiency. The method further reduces the load pressure of a channel in a single-cell coverage area by designing a periodic avoidance algorithm for non-real-time online broadband data calls in the single-cell coverage area. The application has the beneficial effects of further improving the non-priority UVH call loss rate and adding the cell call blocking rate performance on the basis of maintaining the extremely low priority UVH call loss rate, improving the channel use efficiency of the WLAN coverage area, and realizing effective utilization of network channel resources.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, specifically to a time-limited non-real-time data avoidance vertical handover method between heterogeneous networks. Background Technology

[0002] Currently, with the ever-increasing demand for mobile access services, next-generation wireless communication technologies are developing towards interoperability between different wireless networks. Cellular mobile networks and wireless local area networks (WLANs) are two major wireless communication networks in modern wireless communication. Cellular mobile networks are characterized by large coverage and low bandwidth, while WLANs, on the other hand, are characterized by small coverage and high bandwidth. Interoperability between cellular mobile networks and WLANs can allow both to complement each other's advantages, enhancing the Quality of Service (QoS) of the services provided.

[0003] The process of exchanging connections between networks is called handover. Handover between networks using the same access technology (such as WLANs) is called horizontal handover, while handover between networks using different access technologies (such as cellular mobile networks and WLANs) is called vertical handover. Vertical handover can be further divided into downlink vertical handover (DVH) and uplink vertical handover (UVH). For cellular mobile network and WLAN interconnection systems, DVH refers to vertical handover from cellular mobile network to WLAN, while UVH refers to vertical handover from WLAN to cellular mobile network. DVH is the process of a mobile user handing over from a low-bandwidth, high-coverage network to a high-bandwidth, limited-coverage network, while UVH is the process of a mobile user handing over from a high-bandwidth, limited-coverage network to a low-bandwidth, high-coverage network.

[0004] Vertical handoff between heterogeneous networks is a significant challenge for achieving seamless mobility in next-generation mobile networks. In recent years, many handoff methods have emerged for vertical handoff between heterogeneous wireless networks, but few of these methods involve channel preemption. In their 2010 paper "Achannel preemption model for vertical handoff in a WLAN-embedded cellular network" published in the journal *Wireless Networks*, T.-L. Sheu et al. proposed a channel preemption vertical handoff method (PMV method) suitable for interoperability between cellular mobile networks and WLANs. The core idea is that if all effective mobile channels in the cellular mobile network are occupied, new calls within the coverage area of ​​a single cellular mobile network, or handoff calls that have undergone the UVH procedure to switch to a single cellular mobile network coverage area, can preempt any available cellular mobile channels within the dual coverage area of ​​the cellular mobile network and WLAN. The preempted online cellular call is then forced to undergo the DVH procedure, performing a downlink vertical handoff from the cellular mobile network to the WLAN. The PMV method effectively reduces the blocking rate of new calls within the cellular mobile network and the UVH handoff call loss rate. The handling of handover calls directly impacts the Quality of Service (QoS) for mobile users and the performance of interconnection systems. As early as 1996, I. Katzela and M. Naghshineh, in their paper "Channel Assignment Schemes for Cellular Mobile Telecommunication Systems: A Comprehensive Survey" published in the journal "IEEE Personal Communications," pointed out that "the loss of handover calls should be avoided more than the congestion of new calls within a cellular network." However, in the design of cellular mobile channel occupancy and preemption for new calls within a single cell's coverage area and vertical handover calls performing the UVH process to a single cell's coverage area, the PMV method does not consider the order of priority. Instead, it grants UVH handover calls and new cellular calls equal rights to compete for and preempt cellular mobile channels. As a result, the call loss rate performance of UVH handover calls cannot be further improved.To address the shortcomings of the PMV method, the paper "An Upward Priority Channel Preemption Scheme for Vertical Handoff in Cellular / WLAN Interworking" proposed an uplink priority vertical handoff method (UPPS) suitable for cellular mobile networks and WLAN interworking networks at the 2011 IEEE WICOM international conference. This method effectively improves the UVH handoff call loss rate performance by increasing the priority of UVH handoff calls in uplink vertical handoffs with channel preemption, but it also slightly increases the blocking rate of new cellular calls. For limited cellular mobile channel resources, the UVH handoff call loss rate and the blocking rate of new cellular calls are two contradictory aspects; favoring one will degrade the performance of the other. Achieving the optimal balance between the two has always been a focus of attention in the field of wireless communication. In their 2005 paper "A Fair Bandwidth Allocation Scheme for Multimedia Handoff Calls in Cellular Networks" published in the journal *New Trends in Computer Networks*, M. Salamah et al. pointed out that "for online voice calls, users are very annoyed if the call is dropped after a short duration, but their dissatisfaction is less intense when the call is dropped after a certain amount of time; similarly, for online data calls, users can generally tolerate drops when the connection time is less than an acceptable range, but their dissatisfaction is quite strong when the call is dropped after a considerable amount of online data transmission." Based on this, M. Salamah et al. proposed a Time-Threshold Channel Allocation (TTS) method for horizontal handoff in cellular networks. This method monitors the online communication time of horizontal handoff calls and prioritizes them according to users' different tolerance levels for voice and data services. Its aim is to improve the blocking rate performance of new calls while ensuring a low drop rate for priority horizontal handoff calls for time-sensitive users.At the IEEE WICOM'2012 international conference, the paper "A Time-threshold-based Upward Priority Scheme for Vertical Handoff in Cellular / WLAN Interworking" applied the time-threshold strategy for horizontal handoff between similar networks, developed by M. Salamah et al., to vertical handoff between dissimilar networks. This proposed a time-threshold-based uplink vertical handoff method (TUPS method) for dissimilar networks. This method significantly improves the performance of the UPPS method in terms of blocking rate of newly added cellular calls while maintaining high cellular mobile channel utilization and low uplink vertical handoff call loss rate for time-sensitive users. Building on this, the paper "A Time-threshold-based Priority Hopping Scheme for Vertical Handoff in Cellular / WLAN Interworking," published at the 2017 IEEE Computer and Communications international conference, proposed an uplink priority hopping vertical handoff method suitable for cellular mobile networks and WLAN interworking networks (TPHS method). This method, based on the time-threshold-based vertical handover method, proposes a priority-jumping algorithm for call occupancy and channel preemption within cellular coverage areas to adjust the ability of various calls to compete for cellular mobile channels under different environments. Simultaneously, it alleviates channel congestion within cellular coverage areas by designing a DVH decision algorithm for online voice calls in dual coverage areas. In 2022, considering the current common configuration of ultra-large capacity cache chips in mobile terminals and the differences between high-bandwidth WLANs and low-bandwidth cellular networks, patent application number "202210485814.3" proposed a time-limit-based non-real-time data variable-speed vertical handover method (TVVS method) applicable to heterogeneous networks of cellular mobile networks and WLAN interconnection networks. This method dynamically adjusts the transmission rate of non-real-time broadband data calls according to the characteristics of each coverage area; in high-bandwidth WLAN coverage areas, non-real-time broadband data is transmitted at high speed and cached in the mobile terminal's cache chip. This significantly reduces the load pressure on a single cellular coverage area within heterogeneous networks, further improves the system's UVH call loss rate and new cellular call blocking rate performance, and also improves the channel utilization efficiency within WLAN coverage areas. Nevertheless, how to further alleviate the load pressure on single-cell coverage areas within heterogeneous networks to improve the system's non-priority UVH call loss rate and new cell call blocking rate remains an important research objective.Considering that non-real-time online broadband data calls are not time-sensitive and that variable-speed transmission in various coverage areas has greatly improved their transmission efficiency, an algorithm can be designed to periodically avoid non-real-time online broadband data calls in heterogeneous networks within a single cellular coverage area. This can further reduce the load pressure on the channel within the single cellular coverage area. This approach can further improve the performance of non-priority UVH call loss rate and newly added cellular call blocking rate while maintaining the extremely low priority UVH call loss rate of the system, thereby improving the utilization efficiency of WLAN coverage area channels. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a time-limited, non-real-time data avoidance vertical handover method between heterogeneous networks. This method is based on the fact that non-real-time online broadband data calls are not time-sensitive and that variable-speed transmission in various coverage areas has significantly improved transmission efficiency. An improved time-limited, non-real-time data variable-speed vertical handover method is proposed. This method further reduces the channel load pressure within a single cellular coverage area by designing an algorithm for periodic avoidance of non-real-time online broadband data calls within heterogeneous networks. This invention has the beneficial effect of improving the loss rate of non-priority UVH calls and the blocking rate of newly added cellular calls while maintaining a very low priority UVH call loss rate, thereby improving the channel utilization efficiency of WLAN coverage areas and achieving effective utilization of network channel resources.

[0006] The specific technical solution for achieving the objective of this invention is as follows:

[0007] A time-limited, non-real-time data avoidance vertical handover method between heterogeneous networks, wherein the heterogeneous networks refer to those between cellular mobile networks and wireless local area networks, the method comprising:

[0008] a) Classification of online voice and broadband data calls

[0009] By monitoring the online communication time of calls, voice and broadband data time thresholds are set based on users' tolerance for dropped calls. The voice time threshold is a time setting value that exceeds the minimum acceptable call duration for voice users, while the broadband data time threshold is a time setting value that is less than the maximum acceptable online data transmission time for broadband data users. This allows for priority classification of online voice and broadband data calls within the cellular coverage area. Online voice calls with a time lower than the voice time threshold and online broadband data calls with a time higher than the broadband data time threshold are called priority calls, while online voice calls with a time higher than or equal to the voice time threshold and online broadband data calls with a time lower than or equal to the broadband data time threshold are called non-priority calls.

[0010] b) Priority algorithm for call occupancy and channel preemption within heterogeneous cellular coverage areas

[0011] Based on the priority of uplink vertical handover and the user's tolerance for dropped handover calls, the following priority algorithm for channel occupation and preemption is designed for UVH calls (uplink vertical handover calls and new cellular calls) within heterogeneous network cellular coverage areas that require cellular mobile channel occupation and preemption: When there are idle cellular mobile channels within the cellular coverage area, priority UVH calls, non-priority UVH calls, and new cellular calls have the same priority for occupying channels; however, when there are no idle cellular mobile channels within the cellular coverage area, and it is necessary to compete for preemptible cellular channels within the dual coverage area of ​​the cellular network and the wireless LAN, the preemption priority of non-priority UVH calls and new cellular calls jumps to a lower priority level than that of priority UVH calls. In other words, at this time, priority UVH calls have a stronger preemption capability than non-priority UVH calls and new cellular calls.

[0012] c) Online Voice Call (DVH) Decision Algorithm in Heterogeneous Network Dual Coverage Area

[0013] Online voice calls entering the dual coverage area are handled differently according to the call type defined by the voice time threshold. Priority voice calls do not actively execute the DVH process unless other calls in the single cellular coverage area request to preempt it. Non-priority voice calls will abandon the cellular mobile channel and occupy the WLAN wireless channel as long as there is an available WLAN wireless channel. However, if there is no available WLAN wireless channel at this time, non-priority voice calls entering the dual coverage area are allowed to temporarily continue to occupy the cellular mobile channel in the absence of cellular mobile channel preemption, so as to avoid increasing unnecessary online voice drop-offs.

[0014] d) Non-real-time online broadband data call variable speed transmission algorithm during vertical handover process in heterogeneous networks

[0015] Based on the differences between the high bandwidth of WLAN and the low bandwidth of cellular networks, and the fact that mobile terminals are generally equipped with ultra-large capacity cache chips, the data transmission rate of non-real-time online broadband data calls in heterogeneous networks is immediately increased to twice that in a single cellular coverage area after the completion of the DVH process; similarly, the data transmission rate of non-real-time online broadband data calls in heterogeneous networks is immediately reduced to half that in the WLAN coverage area after the completion of the UVH process.

[0016] e) Algorithm for avoiding non-real-time online broadband data calls within the coverage area of ​​a single cell in a heterogeneous network

[0017] In a heterogeneous network single-cell coverage area, the data transmission process of non-real-time online broadband data calls is divided into consecutive communication segments. These segments are categorized into regular communication segments and singular communication segments. Each regular communication segment has a fixed duration of 10 seconds, consisting of a 7-second lead-in transmission period followed by a 3-second avoidance period. Singular communication segments are used to identify communication periods where the remaining dwell time of a non-real-time online broadband data call within the single-cell coverage area is less than 10 seconds. Singular communication segments may contain both a transmission period and an avoidance period, or they may only contain a transmission period. If the duration of a singular communication segment is greater than 7 seconds, then... The lead transmission period remains fixed at 7 seconds. If the duration of the singular communication segment is less than or equal to 7 seconds, there is no grace period within that segment. Non-real-time online broadband data calls within a single cell coverage area can only use idle cellular mobile channels to transmit their data during the transmission period of a communication segment. When the transmission period ends and the grace period begins, the occupied cellular mobile channel must be released, and the caller must wait for the next transmission period to arrive before competing for the cellular mobile channel again to transmit its subsequent data. Non-real-time online broadband data calls during the grace period still need to maintain signaling communication with the base station controlling the single cell coverage area.

[0018] f) Cellular mobile channel allocation within heterogeneous network coverage areas

[0019] The total channel capacity of a cellular cell within a heterogeneous network is W basic bandwidth units. As long as the remaining idle channel capacity of the current cellular cell can meet the service requirements of channel application calls, UVH calls or new cellular calls can occupy cellular mobile channels.

[0020] The interconnection system of this invention has three types of cellular mobile channels: idle cellular channels, preemptible cellular channels, and non-preemptible cellular channels. Preemptible cellular channels refer to the cellular channels occupied by calls within a dual coverage area; non-preemptible cellular channels refer to the cellular channels occupied by calls within a single cellular mobile coverage area.

[0021] In cellular and wireless LAN interconnection systems, online broadband data calls entering dual coverage areas should, as far as possible, execute the DVH (Distributed Virtualization and Hierarchical) procedure. This means that as long as a free WLAN wireless channel exists, such calls should abandon the cellular mobile channel and instead occupy the WLAN wireless channel. However, if no free WLAN wireless channel exists, online broadband data calls entering dual coverage areas are allowed to temporarily continue occupying the cellular mobile channel, provided there is no cellular mobile channel preemption, to avoid unnecessary dropped online broadband data calls.

[0022] The significant difference between this invention and existing technologies is that this invention addresses the non-time-sensitive characteristics of non-real-time online broadband data calls and the fact that variable-speed transmission in various coverage areas has greatly improved transmission efficiency. It designs an algorithm for periodic channel avoidance of non-real-time online broadband data calls within a single-cell coverage area of ​​a heterogeneous network to further reduce the load pressure on the channel within the area. This approach has significant advantages in further improving the performance of non-priority UVH call loss rate and new cellular call blocking rate, and improving the channel utilization efficiency of WLAN coverage areas during uplink vertical handover execution in heterogeneous network environments. Attached Figure Description

[0023] Figure 1 A diagram illustrating the architecture of a cellular mobile network and wireless local area network interconnection system.

[0024] Figure 2 A simulation graph showing the relationship between priority uplink vertical handover call loss rate and cellular load.

[0025] Figure 3 A simulation graph showing the relationship between non-priority uplink vertical handover call loss rate and cellular load.

[0026] Figure 4 A simulation graph showing the relationship between the new cellular call blocking rate and cellular load;

[0027] Figure 5 A simulation graph showing the relationship between cellular mobile channel utilization and cellular load.

[0028] Figure 6 This is a simulation graph showing the relationship between WLAN wireless channel utilization and cellular load. Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are not intended to limit the invention. Variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of the inventive concept are included in the present invention.

[0030] Figure 1The diagram illustrates the architecture of a cellular mobile network / WLAN interconnection system, showing: a single-cell coverage area 1, vertical handover 2, and a dual coverage area 3. This architecture provides voice and broadband data services for cellular mobile terminals and wireless terminals within the WLAN coverage area. In the simulation, the channel capacity W of each cellular cell is 20 BBUs (basic bandwidth unit), and the channel capacity of each WLAN coverage area is 54 BBUs. To meet service QoS requirements, a single voice call requires one basic bandwidth unit of channel space, a single real-time broadband data call and non-real-time broadband data calls within a single-cell coverage area require two basic bandwidth units of channel space, while non-real-time broadband data calls within a WLAN coverage area require four basic bandwidth units of channel space. The process of generating a new call within a cellular cell follows a Poisson process with a mean of λc, while the process of generating a new call within a WLAN coverage area follows a Poisson process with a mean of λw (where λw is 0.04 call / s). The call blocking rate and call loss rate performance indicators involved in this invention are mainly affected by changes in λc. The communication duration of each call follows a negative exponential distribution with a mean of 6 minutes. Online callers' dwell time within a single cell and a single WLAN coverage area follows a negative exponential distribution with mean times of 2 minutes and 4 minutes, respectively. The time thresholds for voice and broadband data used to differentiate between priority and non-priority UVH calls are 120 seconds and 30 seconds, respectively.

[0031] Figure 2 , Figure 3 and Figure 4 Simulation graphs showing the relationship between priority UVH call loss rate, non-priority UVH call loss rate, and new cellular call blocking rate and cellular load are presented respectively. Figure 2 In the middle: the horizontal axis represents cellular call arrival rate; the vertical axis represents priority UVH call loss rate; curve A represents the present invention, and curve B represents TVVS; Figure 3 In the diagram: the horizontal axis represents cellular call arrival rate; the vertical axis represents non-priority UVH call loss rate; curve A represents the present invention, and curve B represents TVVS; Figure 4In the diagram: the horizontal axis represents the cellular call arrival rate; the vertical axis represents the new cellular call blocking rate; curve A represents the present invention, and curve B represents TVVS. Simulation results show that, compared to the TVVS method, the time-limited non-real-time broadband data avoidance transmission vertical handover method between heterogeneous networks proposed in this invention significantly improves the performance of non-priority UVH call loss rate and new cellular call blocking rate while maintaining the system's low-priority UVH call loss rate. This is because, after adopting the avoidance transmission algorithm, the time that non-real-time broadband data calls occupy the channel within a single cellular coverage area is periodically shortened, thereby migrating more non-real-time broadband data call information to the WLAN coverage area for transmission; and the transmission of non-real-time broadband data call information within the WLAN coverage area is performed at twice the rate compared to the single cellular coverage area, thus offsetting the slight delay caused by the periodic avoidance of non-real-time broadband data calls, greatly reducing the congestion of cellular mobile channels within a single cellular coverage area under heavy load conditions. Since non-real-time broadband data calls are non-time-sensitive, this does not affect the QoS of their service transmission. Figure 2 It can be seen that as the average arrival rate λc of new calls in the cell changes, the method of this invention maintains the extremely low priority UVH call loss rate performance of the TVVS method; based on this, Figure 3 In the above, when λc reaches 0.06 calls / s, the non-priority UVH call loss rates of the proposed method and the TVVS method are 1.71E-3 and 8.70E-3, respectively. The proposed method improves the non-priority UVH call loss rate by 80.34% compared to the TVVS method. Similarly, through... Figure 4 It can be further seen that when the average arrival rate λc of new calls in the cell is also 0.06 call / s, the new cellular call blocking rates of the method of the present invention and the TVVS method are 2.75E-3 and 1.10E-2, respectively. The method of the present invention improves the new cellular call blocking rate by 75% compared with the TVVS method, and the improvement effect is quite significant. Figure 5 and Figure 6 Simulation graphs showing the relationship between cellular mobile channel utilization, WLAN wireless channel utilization, and cellular load are presented. Figure 5 In the diagram: the horizontal axis represents cellular call arrival rate; the vertical axis represents cellular mobile channel utilization; curve A represents the present invention, and curve B represents TVVS; Figure 6 In the diagram: the horizontal axis represents cellular call arrival rate; the vertical axis represents WLAN wireless channel utilization; curve A represents the present invention, and curve B represents TVVS. Although Figure 5Compared to the TVVS method, the method of this invention reduces the utilization rate of cellular mobile channels, but this is precisely the design purpose of the method of this invention. By periodically avoiding cellular mobile channels, non-real-time broadband data calls migrate more of their data transmission to the relatively abundant WLAN wireless channels. This method greatly reduces the pressure on channel allocation in cellular coverage areas and can accommodate more online voice and real-time broadband data calls in single-cell coverage areas. Figure 6 This demonstrates that the method of the present invention significantly improves the utilization of WLAN wireless channels compared to the TVVS method. Therefore, from an overall perspective, the overall channel utilization of the system has not decreased; only a portion has migrated from the cellular mobile network to the WLAN network, meaning that the WLAN network shares some of the load with the cellular mobile network.

[0032] Therefore, the analysis of the accompanying drawings and embodiments proves that the time-limited non-real-time data avoidance vertical handover method proposed in this invention, while maintaining the extremely low priority UVH call loss rate, further improves the performance of non-priority UVH call loss rate and new cellular call blocking rate, improves the channel utilization efficiency in the WLAN coverage area, and realizes the effective utilization of channel resources.

Claims

1. A time-limited, non-real-time data avoidance vertical handover method between heterogeneous networks, wherein the heterogeneous networks refer to cellular mobile networks and wireless local area networks, characterized in that, The method includes: a) Classification of online voice and broadband data calls By monitoring the online communication time of calls, voice time thresholds and broadband data time thresholds are set based on users' tolerance for dropped calls. The voice time threshold is a time setting value that exceeds the minimum acceptable call duration for voice users, while the broadband data time threshold is a time setting value that is less than the maximum acceptable online data transmission time for broadband data users. This allows for priority classification of online voice and broadband data calls within the cellular coverage area. Online voice calls with a time lower than the voice time threshold and online broadband data calls with a time higher than the broadband data time threshold are called priority calls, while online voice calls with a time higher than or equal to the voice time threshold and online broadband data calls with a time lower than or equal to the broadband data time threshold are called non-priority calls. b) Priority algorithm for call occupancy and channel preemption within heterogeneous cellular coverage areas Based on the priority of uplink vertical handover and the user's tolerance for dropped handover calls, the following priority algorithm for channel occupation and preemption is designed for UVH calls (uplink vertical handover calls and new cellular calls) within heterogeneous network cellular coverage areas that require cellular mobile channel occupation and preemption: When there are idle cellular mobile channels within the cellular coverage area, priority UVH calls, non-priority UVH calls, and new cellular calls have the same priority for occupying channels; however, when there are no idle cellular mobile channels within the cellular coverage area, and it is necessary to compete for preemptible cellular channels within the dual coverage area of ​​the cellular network and the wireless LAN, the preemption priority of non-priority UVH calls and new cellular calls jumps to a lower priority level than that of priority UVH calls. In other words, at this time, priority UVH calls have a stronger preemption capability than non-priority UVH calls and new cellular calls. c) Online Voice Call (DVH) Decision Algorithm for Downlink Vertical Handover within Heterogeneous Network Dual Coverage Area Online voice calls entering the dual coverage area are handled differently according to the call type defined by the voice time threshold. Priority voice calls do not actively execute the DVH process unless other calls in the single cellular coverage area request to preempt it. Non-priority voice calls will abandon the cellular mobile channel and occupy the WLAN wireless channel as long as there is an available WLAN wireless channel. However, if there is no available WLAN wireless channel at this time, non-priority voice calls entering the dual coverage area are allowed to temporarily continue to occupy the cellular mobile channel in the absence of cellular mobile channel preemption, so as to avoid increasing unnecessary online voice drop-offs. d) Non-real-time online broadband data call variable speed transmission algorithm during vertical handover process in heterogeneous networks Based on the differences between the high bandwidth of WLAN and the low bandwidth of cellular networks, and the fact that mobile terminals are generally equipped with ultra-large capacity cache chips, the data transmission rate of non-real-time online broadband data calls in heterogeneous networks is immediately increased to twice that in a single cellular coverage area after the completion of the DVH process; similarly, the data transmission rate of non-real-time online broadband data calls in heterogeneous networks is immediately reduced to half that in the WLAN coverage area after the completion of the UVH process. e) Algorithm for avoiding non-real-time online broadband data calls within the coverage area of ​​a single cell in a heterogeneous network In a heterogeneous network single-cell coverage area, the data transmission process of non-real-time online broadband data calls is divided into consecutive communication segments. These segments are categorized into regular communication segments and singular communication segments. Each regular communication segment has a fixed duration of 10 seconds, consisting of a 7-second lead transmission period followed by a 3-second avoidance period. Singular communication segments are used to identify communication periods where the remaining dwell time of a non-real-time online broadband data call within the single-cell coverage area is less than 10 seconds. Singular communication segments may contain both a transmission period and an avoidance period, or only a transmission period. If the duration of a singular communication segment is greater than 7 seconds, then the lead transmission period... The transmission period duration remains fixed at 7 seconds. However, if the duration of an unusual communication segment is less than or equal to 7 seconds, there is no grace period within that unusual communication segment. Non-real-time online broadband data calls within a single cell coverage area can only use idle cellular mobile channels to transmit their data during the transmission period of a communication segment. When the transmission period ends and the grace period begins, the occupied cellular mobile channel must be released, and the caller must wait for the next transmission period to arrive before competing for the cellular mobile channel again to transmit its subsequent data. Non-real-time online broadband data calls during the grace period still need to maintain signaling communication with the base station controlling the single cell coverage area. f) Cellular mobile channel allocation within heterogeneous network coverage areas The total channel capacity of a cellular cell within a heterogeneous network is W basic bandwidth units. As long as the remaining idle channel capacity of the current cellular cell can meet the service requirements of channel application calls, UVH calls or new cellular calls can occupy cellular mobile channels.

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