CN105979542A - SDN (Software Defined Network) based WiFi shunting mechanism in 5G heterogeneous network - Google Patents

Abstract

The invention relates to an SDN (Software Defined Network) based WiFi shunting mechanism in 5G heterogeneous network, and belongs to the technical field of mobile communication. The mechanism specifically comprises that when terminal UE sends a service request frame, an SDN controller provides an available AP list for the requesting UE; an SDN monitoring module feeds state information of network equipment and the requesting UE back to a shunt decision-making module of an SDN, channel load judgment is carried out on all APs in the list at first in the shunt decision-making module, the APs which are not overloaded are classified into a group, a channel load value of each AP in the list is calculated, and then the throughout Pw and the effective data receiving rate R(t) of all APs in the list are calculated in sequence; and finally, the channel load value, the throughout Pw and the effective data receiving rate R(t) of each AP are assigned with corresponding weight factors, a utility function QoC of the requesting UE and each AP in the second list is acquired through multiplication and accumulation, the AP with the maximum QoC value is enabled to act as an optimal shunting target, and the requesting UE is notified to access to the target AP so as to realize shunting. The shunting mechanism provided by the invention can realize seamless integration of 5G and WiFi, thereby dealing with explosive increasing of mobile data traffic, effectively solving a severe data overload problem of the cellular network, and improving the user experience under a heterogeneous network environment.

Description

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network

Technical field

The invention belongs to mobile communication technology field, relate to WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network.

Background technology

In recent years, the fast development of mobile terminal and mobile Internet business brings googol according to bearing pressure to cellular network, Mobile data traffic is explosive growth, faces serious data overload problem by causing Cellular Networks.Heterogeneous network (Het-Nets) Become and following 5G network has solved Large Copacity, the wide key network architectural framework covering demand, by wireless access technology (RATs) Realize the access network that in this heterogeneous network, multilamellar is disposed to control.Typical deployment is exactly to be covered with super-intensive chalcid fly in macrocellular Nest, such as Picos, Femtos, via node, WiFi access point etc..Due to the high bandwidth of WiFi wireless network, low cost, Dispose convenient and and Cellular Networks between disturb the characteristics such as little, as the important measures of data traffic of operator's reply sharp increase.

In following 5G communication system, along with the effective integration of mobile network Yu WiFi network, terminal use is poor to both perception Different may disappear, it is achieved user is seamless from mobile network, be transitted smoothly to WiFi network, the seamless of 5G with WiFi melts Credit union allows terminal from being dynamically connected optimal network, experiences to user's unaware.Effectively WiFi shunting mechanism can advantageously promote 5G With the seamless fusion of WiFi, shunt scheme by suitable WiFi, while reducing Cellular Networks overload, carry for user For more reliable service quality, make full use of the Internet resources of each access point so that the resource utilization of whole network maximizes.

Access network discovery and selection function (ANDSF) are the new network elements proposed in the 3GPP R8 stage, have data management and control Function, it is possible to response user carries out the request of access network selection, it is provided that find user access network and carry out access network selection Required assistance data.These information that user provides according to ANDSF, select most suitable access network, it is achieved data service Shunting.But, ADNSF is a kind of strategy based on server, Network finding and selection strategy in mobile network operator domain Pre-configured by Mobile Network Operator, and this type of static configuration do not reflects the current state of (display) access network, no Real-time and Dynamic can obtain network performance index, it is impossible to effectively provide the user with optimal access network.

SDN (Software Defined Network, software defined network) will be controlled by intellectuality as new possible technique The following 5G communication network of system, utilizes OpenFlow agreement, the key-course of router is separated from data Layer, with software Mode realizes.SDN controller can carry out global monitoring to network, grasps the latest tendency of the network equipment in real time, to realizing data Shunting has certain observability.Coordinate to control various network infrastructures with reliable by concentrating based on SDN technology, make data Shunting becomes to be more prone to.

Based on this, the present invention according to the development trend of mobile communication technology, propose in a kind of prospective 5G heterogeneous network based on The WiFi shunting mechanism of SDN.

Summary of the invention

In view of this, it is an object of the invention to provide WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network, should Mechanism is capable of the seamless fusion of following 5G Yu WiFi, the explosive growth of the mobile data traffic of reply, effectively solves honeycomb The serious data overload problem that wire side faces, promotes the Consumer's Experience under heterogeneous network environment.

For reaching above-mentioned purpose, the present invention provides following technical scheme:

In a kind of 5G heterogeneous network, WiFi based on SDN shunting mechanism, merges altogether at a MBS and multiple WiFiAps In the network deposited, realize WiFi shunting mechanism based on SDN framework, specifically include following steps:

S1:SDN controller real time monitoring network status information of equipment, when mobile terminal UE sends service request frame, SDN Controller checks whether this requesting terminal UE periphery exists available WiFiAps, it is allowed to WiFi roams；

S2: if there being the WiFi of permission to roam, i.e. have accessible AP, SDN controller is by APs accessible for requesting terminal UE It is classified as one group, generates list NAP-list1；Otherwise, this request UE remains in current cellular networks；

S3:SDN obtains the network state information of Aps in NAP-list1 list, and according to channel loading conditions, judgement should successively In list, whether the channel loading of Aps exceedes the load threshold Θ of setting, if all exceeding, then requesting terminal UE remains in and works as Front network；Otherwise, list one group and do not transship Aps list, i.e. NAP-list2；

S4: calculate each AP in list NAP-list2 successively according to the APs network state information that SDN controller obtains Handling capacity P_w, and be normalized；

S5: draw in mobile terminal and NAP-list2 list between each AP the data transmission rate at time t according to shannon formula T (t), draws effective data receiver rate R (t)=T (t) (1-Z (t)), and wherein Z (t) is transmission speed error rate, and is marked by R (t) Standardization；

S6: structure utility function: channel loading Load, handling capacity P to AP respectively_wAnd valid data acceptance rate R (t) give The respective weights factor, draws the utility function QoC value between each AP in request UE and NAP-list2 list；

S7: using AP maximum for QoC value as shunting target, SDN controller perform shunting according to Diffluence Algorithm result, Request UE is linked into optimum target AP, it is achieved shunting.

Further, described SDN controller includes two big functional modules: monitoring modular and shunting decision-making module, it is possible to overall situation prison Survey network state information, communicated with the network equipment by OpenFlow agreement, it is achieved the centralized management of Internet resources.

Further, described monitoring modular can carry out reality to the network state of mobile terminal UE and neighbouring BSs and WiFi AP thereof Time monitoring, and the service request of the network information resource of acquisition and mobile terminal is fed back to shunting decision-making module.

Further, described shunting decision-making module receives after the network state information of monitoring modular, first to sending service request The neighbouring available Aps, i.e. NAP-list1 of the mobile terminal UE of frame, carries out channel loading judgement, is classified as by the Aps not transshipped One group, i.e. NAP-list2, channel loading Load are defined according to IEEE 802.11K, formula (1) obtain:

${\mathrm{Load}}_i=\frac{Channel\_Busy\_Fraction}{Measurement\_Duration}---\left(1\right)$

Wherein, Measurement_Duration is channel measurement time, time when Channel_Busy_Fraction is channel busy.

Further, to each AP in list NAP-list2 in shunting decision-making module, this is calculated successively according to formula (2) Handling capacity P of each AP in list_w, and by its normalized:

$P_{w_i}=\frac{{\mathrm{np}}_{tr}{(1-p_{tr})}^{n-1}L}{1+\{{\Σ}_{j=1}^n{(1-p_{tr})}^{n-1}(\frac{L}{C_j}+T_0)+\[1-{(1-p_{tr})}^n-{\mathrm{np}}_{tr}{(1-p_{tr})}^{n-1}\]T_c\}}---\left(2\right)$

Wherein, the number of users during n represents AP；L represents the payload length of user；C_jRepresent speed during telex network； p_trFor the transmission probability under correct transmission state of the user in WiFi；T_oRepresent transport overhead (include detect channel, authenticate with And user attaching etc.)；T_cFor the timeslot number required for each collision time.

Further, shunting decision-making module is according to the link information of each AP in requesting terminal UE and list NAP-list2, respectively Calculate corresponding valid data acceptance rate, and by its standardization, formula be as follows:

1)GC group connector UE and available AP_iLink, it is assumed that linkA width of at the band of time tHz, according to perfume (or spice) Agriculture formula draws terminal UE and AP_iData transmission rate be:

$T_i^{UE}\left(t\right)=b_i^{UE}\left(t\right)(1+\frac{s_i^{UE}\left(t\right)}{n_i^{UE}\left(t\right)})---\left(3\right)$

Wherein,For linkAt the received signal power of time t,For additive white Gaussian noise；

2) due to noise jamming, transmission data have certain error, useRepresent linkAt the error rate of time t, Its computing formula is:

Wherein,

3) outgoing link is obtained by formula (3), (4)Valid data acceptance rate at time t

$R_i^{UE}\left(t\right)=T_i^{UE}\left(t\right)(1-e_i^{UE}(t\left)\right)---\left(5\right).$

Further, channel loading parameter Load, throughput parameter P to AP respectively_wAnd valid data acceptance rate parameter R (t) tax Give respective weights factor-alpha, β, γ, and 0 < α < 1,0 < β < 1,0 < γ < 1, alpha+beta+γ=1, and define requesting terminal UE The available AP with list NAP-list2_iBetween utility function QoC be AP_iLoad Load_i, handling capacityValid data acceptance rateAdd up i.e. with respective weights fac-tor:

${\mathrm{QoC}}_i=\mathrm{\&alpha;}\frac{1}{{\mathrm{Load}}_i}+{\mathrm{\&beta;P}}_{wi}+{\mathrm{\&gamma;R}}_i^{UE}\left(t\right)---\left(6\right).$

Further, taking the maximum AP of QoC value as most preferably shunting target, notice request UE is linked into this target AP, it is achieved point Stream.

The beneficial effects of the present invention is: the present invention, based on SDN platform architecture, utilizes SDN to set by overall situation monitoring network in real time The standby advantage such as status information and outstanding network management capabilities, the network condition information of each access point of Overall Acquisition, and comprehensively examine Consider the access channel loading conditions of AP, handling capacity and the valid data acceptance rate with requesting terminal UE, shown that UE is with available Maximum utility function between AP, selects most preferably to access AP for UE, as shunting target.This shunting mechanism effectively alleviates honeybee The data traffic pressure of the nest network carrying, prevents network congestion situation, promotes the Consumer's Experience under heterogeneous network environment.

Accompanying drawing explanation

In order to make the purpose of the present invention, technical scheme and beneficial effect clearer, the present invention provides drawings described below to illustrate:

Fig. 1 is 5G network scenarios schematic diagram based on SDN；

Fig. 2 is the schematic flow sheet of shunting mechanism of the present invention.

Detailed description of the invention

Below in conjunction with accompanying drawing, the preferred embodiments of the present invention are described in detail.

Fig. 1 is 5G network scenarios schematic diagram based on SDN be applicable to the embodiment of the present invention.In order to meet future network and industry Business demand, in the 5G network architecture based on SDN, it is achieved effective shunt method.In described scene, cover in Cellular Networks In the range of, there are several can re-cover the access point WiFi Aps of lid, its covering radius is far smaller than cellular network, and SDN is positioned at control Preparative layer, is separated data Layer with key-course by OpenFlow agreement, and is led to the network equipment by OpenFlow agreement Letter.Two large divisions is mainly included: monitoring modular and shunting decision-making module in SDN control.Monitoring modular Real-time Monitoring Data layer The network information of equipment, and feed back to shunt decision-making module, perform through Diffluence Algorithm decision-making, select most preferably to access AP for user, Under promoting heterogeneous network environment while Consumer's Experience, also can effectively alleviate the data traffic overload problem of cellular network.

Fig. 2 is the schematic flow sheet of shunting mechanism of the present invention, as it can be seen, the method specifically includes following steps:

1, exist in a MBS coverage, have 1,2 ..., I} the WiFi Aps that can re-cover lid, works as mobile terminal UE When sending service request frame, whether the network equipment state information that SDN controller obtains according to monitoring checks this request UE periphery There is available WiFi Aps, if existing, being classified as one group and can use Aps list (i.e. NAP-list1)；Otherwise, stay on At current cellular networks.

2, during SDN controller obtains NAP-list1 list after the network state information of Aps, according to channel loading computing formula, Adjudicating whether the channel loading of Aps in this list exceedes the threshold values Θ of setting successively, if all exceeding, then requesting terminal UE still stops Currently connecting network；Otherwise, to list one group and do not transship Aps list (i.e. NAP-list2), channel loading formula is:

${\mathrm{Load}}_i=\frac{Channel\_Busy\_Fraction}{Measurement\_Duration}$

Channel loading Load is defined according to IEEE 802.11k, and wherein Measurement_Duration is channel measurement time, Time when Channel_Busy_Fraction is channel busy.

3, after step 2 completes, then calculate respectively each Aps in list handling capacity and and request UE between significant figure According to acceptance rate, and the two is normalized.Computing formula is as follows:

AP_iHandling capacity:

$P_{w_i}=\frac{{\mathrm{np}}_{tr}{(1-p_{tr})}^{n-1}L}{1+\{{\&Sigma;}_{j=1}^n{(1-p_{tr})}^{n-1}(\frac{L}{C_j}+T_0)+\&lsqb;1-{(1-p_{tr})}^n-{\mathrm{np}}_{tr}{(1-p_{tr})}^{n-1}\&rsqb;T_c\}}$

Wherein, the number of users during n represents AP；L represents the payload length of user；C_jRepresent speed during telex network； p_trFor the transmission probability under correct transmission state of the user in WiFi；T_oRepresent transport overhead (include detect channel, authenticate with And user attaching etc.)；T_cFor the timeslot number required for each collision time.

AP_iAnd the valid data acceptance rate between request UE:

S1:GC group connector UE and available AP_iLink, it is assumed that linkA width of at the band of time tHz, according to Shannon formula draws terminal UE and AP_iData transmission rate be:

$T_i^{UE}\left(t\right)=b_i^{UE}\left(t\right)(1+\frac{s_i^{UE}}{n_i^{UE}\left(t\right)})$

Wherein,For linkAt the received signal power of time t,For additive white Gaussian noise.

S2: due to noise jamming, transmission data have certain error, useRepresent linkAt the error rate of time t, Its computing formula is:

Wherein,

S3: obtained outgoing link by S1, S2Valid data acceptance rate at time t

$R_i^{UE}\left(t\right)=T_i^{UE}\left(t\right)(1-e_i^{UE}-(t\left)\right)$

Normalized formula:

$G_w=\frac{P_w-P_{min}}{P_{\max }-P_{min}}$

4, to channel loading parameter Load of AP, throughput parameter P_wAnd valid data acceptance rate parameter R (t) give respective weights Factor-alpha, β, γ, and 0 < α < 1,0 < β < 1,0 < γ < 1, alpha+beta+γ=1.And define requesting terminal UE and available AP_iBetween Utility function QoC be AP_iLoad Load_i, handling capacityValid data acceptance rateTire out with respective weights fac-tor Add i.e.:

${\mathrm{QoC}}_i=\mathrm{\&alpha;}\frac{1}{{\mathrm{Load}}_i}+{\mathrm{\&beta;P}}_{wi}+{\mathrm{\&gamma;R}}_i^{UE}\left(t\right)$

5, taking the maximum AP of QoC value as most preferably shunting target, notice request UE is linked into this target AP, it is achieved shunting.

Finally illustrating, preferred embodiment above is only in order to illustrate technical scheme and unrestricted, although by above-mentioned The present invention is described in detail by preferred embodiment, it is to be understood by those skilled in the art that can in form and In details, it is made various change, without departing from claims of the present invention limited range.

Claims (8)

1. WiFi based on SDN shunting mechanism in a 5G heterogeneous network, it is characterised in that: at a MBS with multiple In the network of WiFiAps amalgamation and coexistence, realize WiFi shunting mechanism based on SDN framework, specifically include following steps:

S1:SDN controller real time monitoring network status information of equipment, when mobile terminal UE sends service request frame, SDN Controller checks whether this requesting terminal UE periphery exists available WiFiAps, it is allowed to WiFi roams；

S2: if there being the WiFi of permission to roam, i.e. have accessible AP, SDN controller is by APs accessible for requesting terminal UE It is classified as one group, generates list NAP-list1；Otherwise, this request UE remains in current cellular networks；

S3:SDN obtains the network state information of Aps in NAP-list1 list, and according to channel loading conditions, judgement should successively In list, whether the channel loading of Aps exceedes the load threshold Θ of setting, if all exceeding, then requesting terminal UE remains in and works as Front network；Otherwise, list one group and do not transship Aps list, i.e. NAP-list2；

S4: calculate each AP in list NAP-list2 successively according to the APs network state information that SDN controller obtains Handling capacity P_w, and be normalized；

S5: draw in mobile terminal and NAP-list2 list between each AP the data transmission rate at time t according to shannon formula T (t), draws effective data receiver rate R (t)=T (t) (1-Z (t)), and wherein Z (t) is transmission speed error rate, and is marked by R (t) Standardization；

S6: structure utility function: channel loading Load, handling capacity P to AP respectively_wAnd valid data acceptance rate R (t) give The respective weights factor, draws the utility function QoC value between each AP in request UE and NAP-list2 list；

S7: using AP maximum for QoC value as shunting target, SDN controller perform shunting according to Diffluence Algorithm result, Request UE is linked into optimum target AP, it is achieved shunting.

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 1, it is characterised in that: Described SDN controller includes two big functional modules: monitoring modular and shunting decision-making module, it is possible to overall situation monitoring network state letter Breath, is communicated with the network equipment by OpenFlow agreement, it is achieved the centralized management of Internet resources.

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 2, it is characterised in that: The network state of mobile terminal UE and neighbouring BSs and WiFi AP thereof can be monitored by described monitoring modular in real time, and will The network information resource obtained feeds back to shunting decision-making module with the service request of mobile terminal.

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 3, it is characterised in that: Described shunting decision-making module receives after the network state information of monitoring modular, first to the mobile terminal sending service request frame The neighbouring available Aps, i.e. NAP-list1 of UE, carries out channel loading judgement, the Aps not transshipped is classified as one group, i.e. NAP-list2, Channel loading Load is defined according to IEEE 802.11K, formula (1) obtain:

${\mathrm{Load}}_i=\frac{Channel\_Busy\_Fraction}{Measurement\_Duration}---\left(1\right)$

Wherein, Measurement_Duration is channel measurement time, time when Channel_Busy_Fraction is channel busy.

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 4, it is characterised in that: To each AP in list NAP-list2 in shunting decision-making module, calculate in this list each successively according to formula (2) Handling capacity P of AP_w, and by its normalized:

$P_{w_i}=\frac{{\mathrm{np}}_{tr}{\left(1-p_{tr}\right)}^{n-1}L}{1+\left\{{\mathrm{\&Sigma;}}_{j=1}^n{\left(1-p_{tr}\right)}^{n-1}\left(\frac{L}{C_j}+T_0\right)+\&lsqb;1-{\left(1-p_{tr}\right)}^n-{\mathrm{np}}_{tr}{\left(1-p_{tr}\right)}^{n-1}\&rsqb;T_c\right\}}---\left(2\right)$

Wherein, the number of users during n represents AP；L represents the payload length of user；C_jRepresent speed during telex network； p_trFor the transmission probability under correct transmission state of the user in WiFi；T_oRepresent transport overhead (include detect channel, authenticate with And user attaching etc.)；T_cFor the timeslot number required for each collision time.

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 5, it is characterised in that: Shunting decision-making module, according to the link information of each AP in requesting terminal UE and list NAP-list2, calculates corresponding respectively Valid data acceptance rate, and by its standardization, formula is as follows:

1)GC group connector UE and available AP_iLink, it is assumed that linkA width of at the band of time tHz, according to perfume (or spice) Agriculture formula draws terminal UE and AP_iData transmission rate be:

$T_i^{UE}\left(t\right)=b_i^{UE}\left(t\right)\left(1+\frac{s_i^{UE}\left(t\right)}{n_i^{UE}\left(t\right)}\right)---\left(3\right)$

Wherein,For linkAt the received signal power of time t,For additive white Gaussian noise；

2) due to noise jamming, transmission data have certain error, useRepresent linkAt the error rate of time t, Its computing formula is:

Wherein,

3) outgoing link is obtained by formula (3), (4)Valid data acceptance rate at time t

$R_i^{UE}\left(t\right)=T_i^{UE}\left(t\right)\left(1-e_i^{UE}\left(t\right)\right)---\left(5\right).$

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 6, it is characterised in that: Channel loading parameter Load, throughput parameter P to AP respectively_wAnd valid data acceptance rate parameter R (t) give respective weights because of Sub-α, β, γ, and 0 < α < 1,0 < β < 1,0 < γ < 1, alpha+beta+γ=1, and define requesting terminal UE and list NAP-list2 In available AP_iBetween utility function QoC be AP_iLoad Load_i, handling capacityValid data acceptance rateWith corresponding power Repeated factor multiplies accumulating i.e. mutually:

${\mathrm{QoC}}_i=\mathrm{\&alpha;}\frac{1}{{\mathrm{Load}}_i}+{\mathrm{\&beta;P}}_{w_i}+{\mathrm{\&gamma;R}}_i^{UE}\left(t\right)---\left(6\right).$

WiFi based on SDN shunting mechanism in a kind of 5G heterogeneous network the most according to claim 7, it is characterised in that: Taking the maximum AP of QoC value as most preferably shunting target, notice request UE is linked into this target AP, it is achieved shunting.