CN104393950B - Single-link time delay based on binary system molecule traffic model determines method - Google Patents

Abstract

A kind of single-link time delay based on binary system molecule traffic model determines method, including procedure below, in binary system molecule traffic model, the transmission of bit 0 or 1 is represented with different molecule types is transmitted, after sender's nano-machines release molecule, molecule is moved in Blang's form in media as well, for the transmission between two nano-machines of single-link, the reliability definition of link is the probability that recipient's nano-machines receive at least one molecule, and time delay is defined as recipient's nano-machines and receives the time that at least one molecule averagely needs.The present invention provides the good single-link time delay based on binary system molecule traffic model of a kind of effective parsing time delay, practicality and determines method.

Description

Single-link time delay based on binary system molecule traffic model determines method

Technical field

It is a kind of list based on binary system molecule traffic model the present invention relates to biotechnology, nanometer technology, the communication technology Link topology network, especially single-link time delay determines method.

Background technology

The fast development of biotechnology and nanometer technology has paved road for the manufacture of the nano-machines of nanoscale size.Receive Rice machine is considered as function device most basic on nanoscale.Nano-machines have preferable application in medical science and industrial circle Prospect.However, the realization that nano-machines are applied in these areas is highly susceptible to the constraint of nano-machines own characteristic, such as The less size of nano-machines and unknown physical property and cause the uncontrollability of nano-machines in the application, it is unstable Property.These problems can be solved by the coordination of nanoscale communication between nano-machines, so that between foring nano-machines Network be referred to as nanometer network.Nanometer network can coordinate the information sharing by way of cooperation of different nano-machines, so as to Enough the completing complexity in the larger context of the tasks.

Molecule communication is a kind of new communication mode between nano-machines, is that one kind is used as information using biochemical molecule Carrier, is spread in biotic environment by molecule and is in communication with each other, for nano-machines to constitute distributed nanometer network The communication technology.The carrier molecule of information is referred to as informational molecule.The basic communication process of molecule communication includes the coding of information, hair Send, transmit, receiving the decode five steps., can be by by sender's nano-machines generation of information in molecular communication system The informational molecule that recipient's nano-machines are recognized and received, and the physically or chemically characteristic encoding information based on informational molecule.Hair The informational molecule of the side's of sending nano-machines release is transferred to after recipient's nano-machines by fluid (liquid or gas) medium, by The reception of recipient's nano-machines and in a particular manner decoded information.

Molecule communication has many superperformances, such as certain types of informational molecule can carry bulk information, can make Nano-machines directly can be interacted with the various primary components in biosystem, with bio-compatibility；In addition, point Sub- communication system can also obtain the energy of abundance from the chemical reaction in environment, to support information transfer.Molecule communication by In not restricted by factors such as the volumes and energy consumption of transceiver, and (such as human body suitable for many specific application environments It is interior), thus academia generally believe based on biology inspire molecule communication be realize that nanometer network is most viable the communication technology it One.

The content of the invention

In order to overcome the shortcomings of the time delay that can not effectively determine of existing single-link topological structure network, the present invention provides a kind of The effectively good single-link time delay based on binary system molecule traffic model of parsing time delay, practicality determines method.

The technical solution adopted for the present invention to solve the technical problems is：

A kind of single-link time delay based on binary system molecule traffic model determines method, and the reliability determines that method includes Following process：

In binary system molecule traffic model, the transmission of 0 or 1 is represented with different molecule types is transmitted, sender receives After rice machine release molecule, molecule is moved in Blang's form in media as well, and a molecule is d from sender's nano-machines to distance Recipient's nano-machines the time required to t probability density function f (t) be：

Wherein, d is the distance between sender's nano-machines and recipient's nano-machines, and D is biotic environment diffusion coefficient；

The corresponding cumulative distribution function F (t) of the probability density function is：

For the transmission between two nano-machines of single-link, the reliability definition of link is received for recipient's nano-machines To the probability of at least one molecule, β is used_ijRepresent, calculated by following formula：

β_ij=1- (1-F (τ))^nN

Wherein, N is the number that sender's nano-machines discharge molecule in each time slot (i.e. time slot), when T is transmission Between, T is divided into n time slot, as T=n τ, n is time slot number, and τ is each time slot durations；

In single-link transmission, time delay be defined as that recipient's nano-machines receive that at least one molecule averagely needs when Between, with E [T_d] represent；For the transmission time needed for d single-link it is m τ for distance, wherein, m is meets in below equation not The minimum value of equation, is at least to receive the minimum time slot corresponding times where a molecule

Wherein, β_ijFor to should link reliability.

Further, for the reliability β under single-link retransmission mechanism_ij' represent, calculation formula is：

Wherein, f_ijFor the maximum retransmission of single-link, β_ijFor the reliability of Successful transmissions single-link.

For the time delay under single-link retransmission mechanism, with E [T_d] ' represent, calculation formula is：

Wherein, f_ijFor the maximum retransmission of single-link, E [T_d] be Successful transmissions single-link time delay, T_ackFor setting Time-out time.

The present invention technical concept be：The bio-compatibility of fully binding molecule communication of the invention, low rate, transmission range The features such as finiteness, higher Loss Rate, main exploitation available for nanometer network by molecule communicate based on it is reliable efficiently Data communication technology.

In binary system molecule traffic model, the transmission of bit 0 or 1 is represented with different molecule types is transmitted.Due to In molecule communication process, the molecule of sender's nano-machines release is diffused transmission in a fluid, causes molecule to reach and connects Debit's nano-machines have higher unreliability and are subject to longer time delay, while considering molecule communication network topology knot Structure has important influence to reliability and time delay.Therefore, binary system molecule traffic model information in multicast scene how is ensured Under the premise of transmission is reliable, it is the key issue for needing to further spread out and further investigate to reduce propagation delay time.

Beneficial effects of the present invention are mainly manifested in：1st, effectively parsing time delay, practicality are good, logical based on binary system molecule Believe model, analyze the reliability of single-link topological structure and the analytical expression of time delay, and the parsing under retransmission mechanism Expression formula.Reliability and time delay are analyzed with the distance between parameter nano-machines by mathematic(al) representation, biotic environment expands Coefficient is dissipated, sender's nano-machines discharge the number of molecule, time slot number, and each in each time slot Time slot durations change showed variation tendency；2nd, the stop-and-wait ARQ based on binary system molecule traffic model (Stop-wait Automatic Repeat reQuest) retransmission mechanism, by controlling maximum retransmission, and determines to receive Square nano-machines reply the Molecules of confirmation (ACK), the probability that ACK molecules are received are improved on to greatest extent, together When ensure that the reliability of transmission, reduce time cost, be greatly reduced complexity.

Brief description of the drawings

Fig. 1 is the topological structure of single-link.Wherein, TN is sender's nano-machines, and RN is recipient's nano-machines.

Fig. 2 is the schematic diagram of the design of the reliable single-link multicast based on binary system molecule traffic model.

Embodiment

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

Referring to Figures 1 and 2, a kind of single-link time delay based on binary system molecule traffic model determines method, including as follows Step：

In order to analyze the case propagation delays based on binary system molecule traffic model under single-link topological structure, single-link is set up Research scene.

Fig. 1 is the topological structure of single-link.Wherein, TN is sender's nano-machines, and RN is recipient's nano-machines.

For the transmission between two nano-machines of single-link, the reliability definition of link for recipient's nano-machines extremely The probability of a molecule is received less, uses β_ijRepresent, calculated with following formula：

β_ij=1- (1-F (τ))^nN

Wherein, N is the number that sender's nano-machines discharge molecule in each time slot.Here, T is transmission time, T is divided into n time slot, as T=n τ, n is time slot number, and τ is each time slot durations.

For the transmission between two nano-machines of single-link, time delay is defined as recipient's nano-machines and receives at least one Time required for individual molecule, with E [T_d] represent.For the transmission time needed for d single-link it is m τ for distance, wherein, m is The minimum value of inequality in below equation is met, when the time slot of minimum are corresponding where as at least receiving a molecule Between.

Wherein, β_ijFor to should link reliability.

Fig. 2 is the design of the reliable efficient single-link scheme based on binary system molecule traffic model.

By ARQ (Stop-wait Automatic Repeat reQuest) retransmission mechanism, analyze and enter based on two The solution of reliability and time delay of the molecule traffic model processed in single-link, single path and multipath under the retransmission mechanism situation Expression formula is analysed, and carries out reliability and delay character analysis in multicast scene on this basis.Ensure that recipient's nano-machines connect Under the premise of the reliability of receipts, the average delay needed for molecule is received is reduced, so as to ensure that the reliable high efficiency of the program.

It is for the Calculation of Reliability formula under single-link retransmission mechanism：

Wherein, f_ijFor the maximum retransmission of single-link, β_ijFor the reliability of Successful transmissions single-link.

For the time delay under single-link retransmission mechanism, with E [T_d] ' represent, calculation formula is：

Wherein, f_ijFor the maximum retransmission of single-link, E [T_d] be single-link Successful transmissions time delay, T_ackFor setting Time-out time.

Claims (2)

1. a kind of single-link time delay based on binary system molecule traffic model determines method, it is characterised in that：During the single-link Prolonging determination method includes following process：

In binary system molecule traffic model, the transmission of 0 or 1, sender's nanometer machine are represented with different molecule types is transmitted After device release molecule, molecule is moved in Blang's form in media as well, a molecule connecing for d from sender's nano-machines to distance T probability density function f (t) is the time required to debit's nano-machines：

$f\left(t\right)=\frac{d}{\sqrt{4{\mathrm{\πDt}}^3}}{e}^{-\frac{d^2}{4Dt}},t>0$

Wherein, d is the distance between sender's nano-machines and recipient's nano-machines, and D is biotic environment diffusion coefficient；

The corresponding cumulative distribution function F (t) of the probability density function is：

$F\left(t\right)=1-Erf\left(\frac{d}{2\sqrt{Dt}}\right),t>0$

For the transmission between two nano-machines of single-link, the reliability definition of link for recipient's nano-machines receive to The probability of a few molecule, uses β_ijRepresent, calculated by following formula：

β_ij=1- (1-F (τ))^nN

Wherein, N is the number that sender's nano-machines discharge molecule in each time slot, and T is transmission time, and T is divided into n Individual time slot, as T=n τ, n are time slot number, and τ is each time slot durations；

In single-link transmission, time delay is defined as recipient's nano-machines and receives the time that at least one molecule averagely needs, and uses E [T_d] represent；For the transmission time needed for d single-link it is m τ for distance, wherein, m is to meet inequality in below equation Minimum value, is at least to receive the minimum time slot corresponding times where a molecule

$E\[T_d\]=\min \{m\mathrm{\τ}:\frac{1}{{\mathrm{\β}}_{ij}}\underset{k=1}{\overset{m}{\Σ}}{(1-F(\mathrm{\τ}\left)\right)}^{N(k-1)}(1-{\left(1-F\left(\mathrm{\τ}\right)\right)}^N)\≥0.5,1\≤m\≤n\}$

Wherein, β_ijFor to should link reliability.

2. the single-link time delay as claimed in claim 1 based on binary system molecule traffic model determines method, it is characterised in that： For the reliability β under single-link retransmission mechanism_ij' represent, calculation formula is：

${{\mathrm{\β}}_{ij}}^{\′}={\mathrm{\β}}_{ij}+(1-{\mathrm{\β}}_{ij}){\mathrm{\β}}_{ij}+{(1-{\mathrm{\β}}_{ij})}^2{\mathrm{\β}}_{ij}+\mathrm{...}+{(1-{\mathrm{\β}}_{ij})}^{f_{ij}}{\mathrm{\β}}_{ij}=\underset{m=0}{\overset{f_{ij}}{\mathrm{\Σ}}}{(1-{\mathrm{\β}}_{ij})}^m{\mathrm{\β}}_{ij}$

Wherein, f_ijFor the maximum retransmission of single-link, β_ijFor the reliability of Successful transmissions single-link；

For the time delay under single-link retransmission mechanism, with E [T_d] ' represent, calculation formula is：

$E{\[T_d\]}^{\′}=2{{\mathrm{\β}}_{ij}}^{2}E\[T_d\]+\underset{m=0}{\overset{f_{ij}}{\Σ}}m{(1-{{\mathrm{\β}}_{ij}}^2)}^m{T}_{ack}$

Wherein, f_ijFor the maximum retransmission of single-link, E [T_d] be Successful transmissions single-link time delay, T_ackFor the time-out of setting Time.