CN102611653B - Bandwidth estimation method based on hybrid network - Google Patents

Abstract

The invention provides a bandwidth estimation method based on a hybrid network. The bandwidth estimation method based on the hybrid network comprises the following steps of: carrying out network available bandwidth estimation, establishing a service flow optimization scheduling unit, configuring a velocity control unit meeting service scheduling fair requirement and the like, thus the high-efficiency utilization of the hybrid network resource and the optimal transmission of a service are realized.

Description

A kind of band width estimation method based on hybrid network

Technical field

The present invention relates to wireless communication technology field, particularly relate to wireless transmission theory.

Background technology

Along with 3-G (Generation Three mobile communication system) progresses into the civilian stage, about the research first meeting clue of future mobile communication system, one of hot issue is wherein exactly that self-organizing network and cellular network are merged to a kind of hybrid network of composition mutually both at home and abroad.Hybrid network has the feature of Cellular Networks and self-organization network concurrently, and its network user utilizes single terminal end both can dynamically form the local subnet in certain limit, enjoys the Service Source of periphery, also can forward by multi-hop the service of access base station acquisition Wide Area Network.Good flexibility and autgmentability make hybrid network become a kind of important composition form of future mobile communication system.Current research institution both domestic and external and researcher have carried out certain research work for hybrid network, propose the solution thinking of many network model imaginations and key technical problem.

At present, the technology that external many research institutions all merge with Cellular Networks mutually to self-organization network has been launched research, try hard to concept and technical for future mobile communication system seek innovation and break through, these networking technologys take full advantage of the advantage of self-organization network and Cellular Networks, obtain good network performance, according to the communication pattern that node support is set of relay forwarding node and the mobility of node.

The wireless network framework that merges Cellular Networks and MANET is a kind of hybrid network model with plurality of communication schemes that Bell Laboratory and University of California propose, each node under this model possesses two kinds of air interfaces simultaneously, make its both supporting cellular link also support the point-to-point broadcasting link based on PQRSTTU.Packet mutual between user terminal and base station both can directly communicate by the wireless link between user terminal and base station, also can first utilize the PQRSTTU broadcast channel multi-hop of point-to-point to be transmitted to proxy user, then utilize wireless link to communicate by proxy user and base station.

The bandwidth estimation of hybrid network is generally to utilize the available bandwidth of the historical information estimation network of TCP connection, available information content is more, available bandwidth is estimated will be more accurate, thereby just can be better and the more fair Internet resources that utilize, this is the principle that existing various bandwidth estimation technique is acted on.On link, the size of available bandwidth depends on: the band width in physical of bottleneck link on (1) transmission path; (2) quantity of the connection of competition same link, the category of model structure of hybrid network as shown in Figure 1.

Because TCP injects the particularity of bag time and the inaccuracy of the TCP source measurement ACK time interval and the minimum RTT of estimation in network, there will be following problem, these problems finally can have influence on bandwidth estimation:

(1) poly-(Clustering);

(2) ACK compression (ACK Compression);

(3) TCP coarseness clock mechanism (TCP coarse.grained clocks);

(4) re-route (Rerouting);

(5) cluster (Clustering);

Message segment during the different TCP of shared same link connect can not mix, and the message segment sending continuously in same connection is to take link bandwidth completely within their a period of time of transmission.Therefore,, for correct estimated bandwidth, TCP source detects oneself utilizes the time of link must be greater than the transmission time of whole string bag, in addition, also needs time enough so that all samplings are taken into account for the filtering technique of level and smooth bandwidth sampling.The quantity of connection and the size of message segment string that the suitable minimum detection time is depended on shared link, namely depend on bandwidth--delay product.Conventional band width estimation method comprises mean square root method (RMSM), correlation method, the methods such as maximum entropy method (MEM) (MEM) and concentration of energy method (EIM).

Therefore,, for ensureing the efficient utilization of hybrid network resource, need band width estimation method reasonable in design.

Summary of the invention

Technical problem to be solved by this invention is: what solve hybrid network resource efficiently utilizes problem.

The present invention provides a kind of band width estimation method based on hybrid network for solving the problems of the technologies described above, and it is characterized in that:

A, carry out hybrid network estimation of available bandwidth;

B, set up Business Stream Optimized Operation unit;

C, arrange and meet the fair speed control unit requiring of business scheduling.

In described steps A, order for transmitting terminal receives the time of individual ACK information, for receiving terminal receive the size of individual packet, in the time that ACK information is back to transmitting terminal, transmitting terminal is by rule obtain the estimated value of available bandwidth, wherein , value rule be: if , if, , .

In described step B, set up Business Stream Optimized Operation unit.It is made up of adaptive controller, parameter estimation unit, general minimum variance (GMV) control unit and active queue management module.Business Stream Optimized Operation cell operation flow process is: a. arranges initial value with ; B. getting sequence number is input and output data; C. use calculate evaluated error; D. use obtain estimated gain; E. calculate obtain estimated value ; F. service regeulations upgrade , wherein the system equation of Business Stream Optimized Operation unit is , ,

, for forgetting factor, total workflow as shown in Figure 2.

In described step B, the closed-loop transfer function of GMV control unit is , wherein , , , , for adjustable parameter.Business Stream is through GMV control unit, then used the rule of new Slow start threshold and the renewal of congestion control window is adjusted Business Stream by active queue management unit and TCP congestion window adjustment unit, update rule is: if congestion control window is not less than Slow start threshold value , the size of congestion control window equals Slow start threshold value ; If congestion control window is less than Slow start threshold value , congestion control window keeps initial value, wherein for Slow start threshold value, for the minimum RTT time, for the average of data package size.Then Business Stream is by delay cell and buffer unit processing, obtain the Business Stream of output, parameter estimation unit compares outgoing traffic stream and incoming traffic stream, then according to the comparison information obtaining, GMV control unit is adjusted, make hybrid network energy according to the adaptive qos requirement that meets business of Business Stream constantly changing, its flow process as shown in Figure 3.

In described step C, speed control unit is made up of business flow rate controller and Business Stream Optimized Operation unit, and rate controller is by system gain module , conversion module , adder and two continuous contention access time interval module composition, its structure as shown in Figure 4.Wherein for continuous interference model, for single steplike function, for time delay.

Beneficial effect of the present invention is: the band width estimation method that a kind of hybrid network is provided, by carrying out network availability bandwidth estimation, set up Business Stream Optimized Operation unit, steps such as meeting the fair speed control unit requiring of business scheduling being set, the efficient utilization of hybrid network resource and the optimized transmission of business are realized.

Brief description of the drawings

Fig. 1 is the category of model structural representation of hybrid network, wherein A-GSM is the GSN network of supporting Ad hoc mode, Dwill adopts handling up of directional technology to strengthen surname Wireless Local Loop, HWN is mixed wireless network model, iCAR is for supporting relaying honeycomb and self-organizing integrated system, MADF is the data retransmission auxiliary based on mobile node, MCN is multi-hop cellular network, MWLAN is multihop wireless lan, MuPAC is many power grouped data cellular network, ODMA is the multiple access model of opportunity driven, PARCER is the cellular network of supporting self-organizing relaying, SMCN is single air interface multi-hop cellular network, SOPRANO is grouping multi-hop wireless net, Sphinx is novel mixed wireless network model, TWILL is the local ring of the enhanced wireless of handling up, UCAN is the wireless network framework that merges Cellular Networks and self-organizing network, UTRA is wireless universal access module,

Fig. 2 is total workflow schematic diagram;

Fig. 3 is control unit and the management process schematic diagram of administrative unit to business of design;

Fig. 4 is speed control unit structural representation.

Claims (1)

1. the band width estimation method based on hybrid network, what solve hybrid network resource efficiently utilizes problem, comprises the steps:

A, carry out network availability bandwidth estimation, be specially and make t _kfor the time that transmitting terminal is received k ACK information, d _kthe size of k the packet of receiving for receiving terminal, in the time that ACK information is back to transmitting terminal, transmitting terminal is by rule obtain the estimated value of available bandwidth, wherein BW _e(k)=BW _e(k-1) α+BW (k) (1-α), the value rule of α is: if BW (k)>=BW _e(k-1), $\mathrm{\&alpha;}=\frac{{\mathrm{BW}}_e(k-1)}{\mathrm{BW}\left(k\right)},$ If BW (k) is <BW _e(k-1), $\mathrm{\&alpha;}=\frac{\mathrm{BW}\left(k\right)}{{\mathrm{BW}}_e(k-1)};$

B, set up Business Stream Optimized Operation unit, the closed-loop transfer function that is specially GMV control unit is wherein E (z ^-1)=e ₀+ e ₁z ^-2+ ... + e _d-1z ^-(d-1), F (z ^-1)=f ₀+ f ₁z ^-2+ ... + f _n-1z ^-(n-1), R ₀, q ₀for adjustable parameter, Business Stream is through GMV control unit, then use the rule of new Slow start threshold and the renewal of congestion control window is adjusted Business Stream by active queue management unit and TCP congestion window adjustment unit, update rule is: if congestion control window is not less than Slow start threshold value ω, the size of congestion control window equals Slow start threshold value ω; If congestion control window is less than Slow start threshold value ω, congestion control window keeps initial value, wherein for Slow start threshold value, RTT _minfor the minimum RTT time, for the average of data package size, then Business Stream is by delay cell and buffer unit processing, obtain the Business Stream of output, parameter estimation unit compares outgoing traffic stream and incoming traffic stream, then according to the comparison information obtaining, GMV control unit is adjusted, can be according to the adaptive qos requirement that meets business of the Business Stream of continuous variation;

C, arrange and meet the fair speed control unit requiring of business scheduling, speed control unit is made up of business flow rate controller and Business Stream Optimized Operation unit, and rate controller is by system gain module k _i, z conversion module z ^-1, adder, and the time interval module T of two continuous contention access _cAcomposition, wherein for continuous interference model, l (k) is single steplike function, t _jfor time delay.