CN103067977B - Data concurrence transmission method based on cross-layer optimization in wireless heterogeneous network system - Google Patents

Abstract

The present invention relates to a data concurrent transmission method based on cross-layer optimization in a wireless heterogeneous network system. A new protocol layer is constructed between the layer and the data link layer, which is the cross-layer processing layer, and a virtual network card is constructed at the cross-layer processing layer; when the data transmitted from the server reaches the gateway, the IP data packet is extracted at the network layer of the gateway At the same time, the gateway detects the channel quality information of each wireless heterogeneous network; the cross-layer processing layer distributes the IP data packets to be sent to each wireless heterogeneous network according to the detection results, and sends them to the terminal equipment; The data packet is put into the receiving buffer, and the IP data packet in the buffer is reordered and processed. The invention can improve the end-to-end transmission rate of the network, reduce the service end-to-end transmission time delay, and realize the balanced transmission of concurrent data in the wireless heterogeneous network system.

Description

A data concurrent transmission method based on cross-layer optimization in a wireless heterogeneous network system

technical field

The invention relates to the field of wireless communication, in particular to a data concurrent transmission method based on cross-layer optimization in a wireless heterogeneous network system.

Background technique

In recent years, wireless communication technology has made great progress, and various new wireless communication concepts and technologies emerge in an endless stream, forming a wireless heterogeneous network with multiple systems coexisting. At the same time, with the rapid development of mobile Internet and communication technology, people's quality of life is gradually improving, and diversified smart terminals are becoming popular. People's demand for the capacity, speed, flexibility and quality of communication networks is increasing day by day. Due to the low end-to-end throughput and high delay, the network can no longer meet the existing needs, and many cellular network providers are beginning to feel very anxious about the shortage of wireless communication resources. Therefore, from the perspectives of limited resources, operational effectiveness, and diverse business needs of users, it is necessary to make full use of the complementary characteristics of different networks to realize the organic integration and collaborative sharing of wireless heterogeneous network technologies, so as to provide more Optimized network performance and more flexible and reliable services, so as to realize the true self-organization and self-adaptation of wireless communication networks, and realize the interconnection and intercommunication between networks.

As one of the research hotspots and effective means of interworking and integration of wireless heterogeneous networks, joint radio resource management has received extensive attention and research in recent years. Joint radio resource management in a wireless heterogeneous network system is a collection of control mechanisms for multiple coexisting networks, including intelligent session admission control, adaptive management of service types and transmission rates, and optimal allocation of system power and Control, etc., so as to realize the effective use of wireless resources and achieve the goal of system performance optimization. However, in the past, the research on joint radio resource management mainly focused on the selection of a specific network when providing services, so as to take advantage of the technical advantages of a single network. Although other networks in the heterogeneous network environment were also considered, as a joint The multi-mode or reconfigurable technology, one of the foundations of radio resource management, has not been fully utilized. Technically, with the support of multi-mode technology or reconfigurable technology, terminals with multiple sets of antennas have the ability to simultaneously access the The ability of multiple radio access networks, thus a new concept of radio resource management emerges: that is, to divide a single service data flow, and transfer the sub-data flows to multiple networks for parallel transmission. In this way, the advantages of multiple networks can be fully utilized, and wireless heterogeneous networks can cooperate with each other to provide users with better services.

Contents of the invention

The purpose of the present invention is to address the deficiencies of the above-mentioned existing technologies, and propose a data concurrent transmission method based on cross-layer optimization in a wireless heterogeneous network system, so as to improve the network end-to-end transmission rate and reduce the service end-to-end transmission delay. Realize the balanced transmission of concurrent data in the wireless heterogeneous network system.

In the present invention, on the one hand, the data is distributed to each network in a fair and reasonable manner by obtaining the distribution parameters of concurrent data transmission as the basis of the distribution strategy; on the other hand, at the receiving end, the received IP data packets are reordered to ensure IP data packets are submitted to the upper layer of the protocol stack in sequence.

A data concurrent transmission method based on cross-layer optimization in a wireless heterogeneous network system is characterized in that the following steps are performed:

(1), defining a gateway as a convergence point between a server and a terminal access point for multiple wireless heterogeneous networks;

(2), a new protocol layer is constructed between the network layer and the data link layer of the gateway, which is called the cross-layer processing layer, and a virtual network card is constructed at the cross-layer processing layer;

(3), when the data transmitted from the server arrives at the gateway, the IP packet is extracted at the network layer of the gateway;

(4), the gateway detects the channel quality information of each wireless heterogeneous network; wherein, step (3) and step (4) are two parallel processing processes;

(5) The cross-layer processing layer distributes the IP data packets to be sent to each wireless heterogeneous network according to the detection results, and sends them to the terminal equipment;

(6) The terminal receives data, puts the received IP data packets into the receiving buffer, and performs a reordering processing routine on the IP data packets in the buffer.

The concrete realization method of step (4) of the present invention is:

The gateway sends an Internet Control Message Protocol ICMP (Internet Control Message Protocol) packet to the terminal at a fixed time T at the same time through all wireless heterogeneous networks to update the end-to-end round-trip delay RTT (Round RTT) of each wireless heterogeneous network -Trip Time).

The RTT is updated as follows:

RTT=α×(RTT _new )+(1-α)×(RTT _old )

Among them, RTT _new is the end-to-end round-trip delay of the wireless heterogeneous network at the current moment, RTT _old is the end-to-end round-trip delay of the wireless heterogeneous network at the previous moment, and α represents the RTT historical impact factor, which is generally taken as 0.125.

Step (5) concrete realization method of the present invention is:

Firstly, the transmission capability of the wireless heterogeneous network is characterized by the ratio of the available bandwidth W of the physical layer of the wireless heterogeneous network to the end-to-end round-trip delay RTT, and then the transmission capacity of each wireless heterogeneous network is calculated as a percentage of the total wireless heterogeneous network. The ratio of the transmission capacity, the data packet is sent to each network with the probability of the ratio value.

The specific implementation method of the reordering processing routine of step (6) is as follows:

At the receiving end, set a reordering window with a certain width in the entire available SN (data packet sequence number) interval, and the window width does not exceed the number of SNs-1, and the lower edge of the window is the SN number currently expected to be received; if the received SN If it falls outside the window, the data packet is discarded; if the received SN happens to be the lower edge of the window, then the window is moved, and the continuous and received data packets starting from the lower edge are submitted to the upper layer in sequence; If the SN falls within the window but is not the lower edge of the window, it is inserted into the window queue; in addition, a periodic polling task is started, and if there is a data packet in the window that has not been submitted overtime, the lower edge of the window is forced to be moved to after the data packet, And submit the received data packets out of the window to the upper layer in sequence.

Compared with the prior art, the present invention has the following advantages:

(1) The present invention distributes data to several different wireless heterogeneous networks for transmission, which has higher end-to-end throughput and lower delay than data centralized transmission in a single network.

(2) By constructing a new protocol layer, that is, the cross-layer processing layer, the present invention combines the channel quality information measured at the physical layer and the network layer to measure the transmission capabilities of each wireless heterogeneous network, and according to each wireless heterogeneous The transmission capacity of the network allocates a corresponding proportion of data flow, so that the amount of data sent to each wireless heterogeneous network matches the current real transmission capacity. On the one hand, it achieves load balancing to a certain extent; on the other hand, it can significantly improve the end-to-end throughput of the business and reduce the service transmission delay when the business volume is large.

(3) The present invention constructs a new protocol layer between the network layer and the link layer, that is, the cross-layer processing layer, and performs shunting at the cross-layer processing layer. Compared with shunting at the application layer and the transport layer, the utility of shunting Higher, that is, to obtain higher transmission flexibility and bandwidth utilization; compared with splitting at the link layer, complex issues such as data sorting and synchronization are easier to deal with.

(4) The present invention avoids the out-of-sequence problem of data packets received by the receiving end caused by the different end-to-end delays of various wireless heterogeneous networks by reordering the IP data packets at the receiving end, ensuring IP data packets are submitted sequentially to the upper layer of the protocol stack.

Description of drawings

FIG. 1 is a schematic diagram of the system structure of an embodiment of the present invention.

Fig. 2 is a diagram of functional modules contained in each node in the system of the embodiment of the present invention.

FIG. 3 is a general flowchart of the method for concurrent data transmission based on cross-layer optimization in the present invention.

Detailed ways

The present invention will be further described in conjunction with the accompanying drawings.

This article will take FIG. 1 as an example to describe in detail the concurrent data transmission method based on cross-layer optimization in a wireless heterogeneous network system, but is not limited to the network topology shown in FIG. 1 .

Fig. 1 is the system structural diagram of the embodiment of the present invention, and this system is made up of two wireless heterogeneous networks of LTE and WLAN; The whole wireless heterogeneous network system comprises two multimode terminals, a gateway and an LTE link and two WLAN link, wherein the gateway is the aggregation point between the server and the terminal access point of each wireless heterogeneous network.

Fig. 2 is a schematic diagram of the functional modules contained in each node in the system. The present invention is only for the gateway and the terminal, and some functional modules are added on the basis of the existing functional modules. Since the gateway and the terminal are two peer entities, the gateway and the terminal A cross-layer processing layer is added everywhere, and three functional modules of virtual network card, shunt and reordering are implemented in the cross-layer processing layer to realize the concurrent data transmission function based on cross-layer optimization of gateways and terminals.

Fig. 3 is the general flow chart of the data concurrent transmission method based on cross-layer optimization of the present invention, and this method comprises:

Step 1: Define the gateway as the aggregation point between the server and the terminal access point for multiple wireless heterogeneous networks;

Step 2: Construct a new protocol layer between the network layer and the data link layer of the gateway, called the cross-layer processing layer, and construct a virtual network card at the cross-layer processing layer;

Step 3: When the data from the server arrives at the gateway, extract the IP data packet at the network layer of the gateway;

Step 4: The gateway detects channel quality information of each wireless heterogeneous network;

As shown in Figure 3, Step 3 and Step 4 are two parallel processing processes, and the specific implementation method of Step 4 is as follows:

Every fixed time T, the gateway sends an ICMP packet to the terminal through all wireless heterogeneous networks at the same time to update the end-to-end round-trip delay RTT of each wireless heterogeneous network;

The RTT is updated as follows:

RTT=α×(RTT _new )+(1-α)×(RTT _old )

Among them, RTT _new is the end-to-end round-trip delay of the wireless heterogeneous network at the current moment, RTT _old is the end-to-end round-trip delay of the wireless heterogeneous network at the previous moment, and α represents the RTT historical impact factor, which is generally taken as 0.125.

Step 5: distribute the IP data packets to be sent to each wireless heterogeneous network according to the detection results, and send them to the terminal equipment;

Its specific implementation is as follows:

(1) Calculation: the ratio of the available bandwidth W of the physical layer of the wireless heterogeneous network to the end-to-end round-trip delay RTT, and obtain the transmission capability P of the heterogeneous wireless network;

(2) Calculate the ratio of the transmission capacity of each wireless heterogeneous network to the total transmission capacity of all wireless heterogeneous networks according to the following formula;

${\mathrm{<span\; class="notranslate">\; \&eta;</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; =</span>\frac{\frac{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}{{\mathrm{<span\; class="notranslate">\; RTT</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}}{\frac{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; RTT</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}}<span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; RTT</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; +</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; +</span>\frac{{\mathrm{<span\; class="notranslate">\; W</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; RTT</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; \&le;</span>\mathrm{<span\; class="notranslate">\; no</span>}$

In the above formula, η _i represents the ratio of the transmission capacity of wireless heterogeneous network i to the total transmission capacity of all wireless heterogeneous networks, W _i represents the available bandwidth of the physical layer of wireless heterogeneous network i, and RTT _i represents the current wireless heterogeneous network network The end-to-end round-trip delay of i, n represents the number of wireless heterogeneous networks, and i represents an integer between 1 and n;

(3) Use the ratio value η _i calculated in the above step (2) as the probability to determine the sending network of the IP data packet. Specifically, the range from 0 to 1 is first determined by the ratio value η _i (1≤i≤n) Divide into n intervals that do not overlap with each other, that is, each interval corresponds to a wireless heterogeneous network, and then generate a random number from 0 to 1. The random number falls in a certain interval and corresponds to a wireless heterogeneous network. The structured network is the network where the IP datagrams will be sent.

Step 6: The terminal receives the data, puts the received IP data packets into the receiving buffer, and performs reordering processing routines on the IP data packets in the buffer.

With reference to the reordering processing routine in Figure 3, its specific implementation method is as follows:

At the receiving end, set a reordering window with a certain width in the entire available SN interval, and the window width does not exceed the number of SNs -1, and the lower edge of the window is the SN number (sequence number) that is currently expected to be received; if the received SN falls within If the received SN is just at the lower edge of the window, then move the window and submit the continuous and received data packets from the lower edge to the upper layer in sequence; if the received SN falls In the window but not at the lower edge of the window, insert it into the window queue; in addition, start a periodic polling task, if there is a data packet in the window that is timed out and unsubmitted, the lower edge of the window is forced to move to after the data packet, and upward Layers sequentially submit received packets that move out of the window.

Claims (5)

1. in Wireless Heterogeneous Networks system based on the data concurrency transmission method of cross-layer optimizing, it is characterized in that carrying out according to the following steps:

(1), defining gateway is the convergent point of multiple Wireless Heterogeneous Networks between server and terminal accessing-point;

(2), between the network layer and data link layer of gateway construct a new protocol layer, be called cross-layer processing layer, simultaneously at cross-layer processing layer constructing virtual network interface card;

(3), when the data, from server transmitted arrive gateway, IP packet is extracted in the network layer of gateway;

(4), gateway detects the channel quality information of each Wireless Heterogeneous Networks; Wherein, step (3) and step (4) are two parallel process;

(5) the cross-layer processing layer IP allocation of packets that will send according to testing result is in each Wireless Heterogeneous Networks, sends to terminal equipment;

(6) terminal receives data, and the IP packet received is put into reception buffer zone, and to reorder process routine to the IP packet in buffering area.

2. in Wireless Heterogeneous Networks system according to claim 1 based on the data concurrency transmission method of cross-layer optimizing, it is characterized in that: the concrete methods of realizing of described step (4) is:

Gateway is every set time T, send an Internet Control Message agreement ICMP(Internet Control Message Protocol by all Wireless Heterogeneous Networks to terminal simultaneously) bag, upgrade the end-to-end round-trip delay RTT(Round-Trip Time of each Wireless Heterogeneous Networks).

3. in Wireless Heterogeneous Networks system according to claim 2 based on the data concurrency transmission method of cross-layer optimizing, it is characterized in that: described RTT completes renewal as follows:

RTT=α×(RTT _new)+(1-α)×(RTT _old)

Wherein RTT _newfor the end-to-end round-trip delay of current time wireless isomer network, RTT _oldfor the end-to-end round-trip delay of a upper moment Wireless Heterogeneous Networks, α represents the RTT historical influence factor, generally gets 0.125.

4. in Wireless Heterogeneous Networks system according to claim 1 based on the data concurrency transmission method of cross-layer optimizing, it is characterized in that: described step (5) concrete methods of realizing is:

First the transmittability of Wireless Heterogeneous Networks is characterized by the physical layer available bandwidth W of Wireless Heterogeneous Networks and the ratio of end-to-end round-trip delay RTT, then calculate the ratio that each Wireless Heterogeneous Networks transmittability accounts for the total transmittability of all Wireless Heterogeneous Networks, by packet with this ratio value size for probability is sent to each network.

5. in Wireless Heterogeneous Networks system according to claim 1 based on the data concurrency transmission method of cross-layer optimizing, it is characterized in that: described step IP packet carry out the reordering concrete methods of realizing of process routine is as follows: at receiving terminal, the certain window that reorders of a width is set in whole available SN (packet sequence number) interval, and window width is no more than SN number-1, lower window edge and current No. SN of expecting reception; If the SN received drops on outside window, then abandon this packet; If the SN received is just for lower window edge, then moving window, to upper strata submit to according to the order of sequence from lower along, continuous print, the packet received; If the SN received to drop in window but is not lower window edge, be then inserted in window queue; In addition, start one-period polling tasks, if there is packet time-out not submit in window, then forces along after this packet under moving window, and submit packet outside grand window, that receive to upper strata according to the order of sequence to.