CN105848221B

CN105848221B - Resource share method between operator under multiple business scene based on network virtualization

Info

Publication number: CN105848221B
Application number: CN201610024622.7A
Authority: CN
Inventors: 尤肖虎; 夏婷; 潘志文; 刘楠
Original assignee: Southeast University
Current assignee: White Box Shanghai Microelectronics Technology Co ltd
Priority date: 2016-01-14
Filing date: 2016-01-14
Publication date: 2019-08-13
Anticipated expiration: 2036-01-14
Also published as: CN105848221A

Abstract

The invention discloses resource share methods between the operator based on network virtualization under one kind of multiple business scenarios.Comprising: provide the utility function of different business user first, the frequency spectrum resource allocation method that operator when without using network virtualization is directed to the different business user of oneself is then designed.It is shared finally, being focused on the frequency spectrum resource of multiple operators in one physical base station using network virtualization, and designs the frequency spectrum resource allocation method of the different business user for all operators.Using the resource share method in the present invention, user satisfaction can be significantly improved, realizes and improves system performance and guarantee the tradeoff between user fairness, improve frequency spectrum resource utilization rate.

Description

Inter-operator resource sharing method based on network virtualization under various service scenes

Technical Field

The invention relates to the problem of resource sharing among operators in network virtualization, and belongs to the technical field of network virtualization in wireless communication.

Background

In recent years, with the increasing popularity of smart phones, notebooks and other wireless devices, the demand for mobile data has increased dramatically. In order to increase the capacity of the mobile network to meet the data demand, mobile network operators use many technologies, such as broadband air interface technology using Multiple Input Multiple Output (MIMO) system to obtain higher rate, small cell technology, and the like. These techniques, however, increase the capital and operational expenditure of the network, increasing the complexity of the network. In addition, the method of increasing system capacity by acquiring new radio spectrum resources also requires a large amount of upfront investment. The network virtualization technology shares spectrum resources and infrastructure through a plurality of operators, improves resource utilization rate and system throughput, and reduces network capital and operation expenditure.

Network virtualization refers to a technology in which a physical resource can be abstracted and divided into a plurality of virtual network resources isolated from each other to be shared by multiple parties. Network virtualization divides a traditional network service provider into two new roles: infrastructure network providers (InP) and Service Providers (SP). SPs provide various services by leasing resources to InP to establish virtual networks. Network virtualization obviously improves the resource utilization rate, realizes the decoupling of functions and facilities, and is easy to realize the expansion and management of new services and products, thereby reducing the equipment and management cost.

In reality, users using different services have different Quality of Service (QoS) requirements. Utility functions may be used to describe the QoS requirements of users. The utility function takes the user rate as an independent variable, and can reflect the satisfaction degree when a user reaches a certain speed after dividing resources. The problem of allocating resources to different service users based on Utility is often modeled as a Network Utility and Maximization (NUM) problem, which can improve system throughput while ensuring fairness among users.

When network virtualization is not used, the operators allocate resources individually. Through network virtualization, all operators can centralize frequency spectrum resources on one physical base station, and the physical base station distributes all the frequency spectrum resources to each virtual base station for different operators to use, so that the method has higher resource sharing flexibility and resource utilization rate. After the resources are shared, not only the quality of service of users of each operator is ensured not to be reduced, but also the fairness of performance gain among the operators is ensured.

Disclosure of Invention

The invention aims to provide a method for realizing resource sharing among different operators by using network virtualization under the scene of multiple service users, and designs a spectrum resource allocation method, which can maximize the system utility, ensure that the user satisfaction of each operator is not lower than the satisfaction of each operator when virtualization is not used, and ensure the fairness of performance gain among the operators. By adopting the resource sharing method, the user satisfaction can be obviously improved, the balance between the improvement of the system performance and the guarantee of the user fairness is realized, and the utilization rate of the frequency spectrum resources is improved.

The invention firstly provides utility functions of three different service users, and then designs a spectrum resource allocation method for different service users of an operator when network virtualization is not used. And finally, using network virtualization to centralize the spectrum resources of a plurality of operators into one physical base station for sharing, and designing a spectrum resource allocation method aiming at different service users of all operators.

1 utility function of three different service users

The invention divides users with different services into three types: users with Hard QoS requirements (Hard QoS, HQ), users with flexible QoS requirements (Soft QoS, SQ) and users without QoS requirements (Best Effort, BE). The user satisfaction is set between 0 and 1.

1) HQ users

The HQ user only satisfies the rate requirement, and its utility function is a unit step function defined as follows:

wherein U is^HIs the utility of HQ users, r^dIs the rate requirement of the user and r is the rate of the HQ user.

2) SQ user

SQ users have more flexibility with respect to rate requirements than HQ users. The utility function has the following characteristics:

A. when r is more than or equal to 0 and less than r^dWhen dU (r)/dr > 0, d²U(r)/dr²> 0, the utility function is a convex function.

B. When r is more than or equal to r^dWhen dU (r)/dr > 0, d²U(r)/dr²< 0, the utility function is a concave function.

C. When r is r^dWhen d is greater than²U(r)/dr²This point is the inflection point of the utility function, 0.

The utility function for an SQ user with the above conditions is:

wherein U is^STo the utility of SQ users, β₁For a parameter that can adjust the slope of the utility function curve, β₁Is that when r is equal to r^dThe utility of SQ users. p is a radical of₁The method is another parameter which can adjust the slope of the utility function curve and reflect the flexibility of the user for the speed requirement.

3) BE users

Since BE users have no specific rate requirements, we set r^dWhen 0, the utility function is:

wherein U is^BFor the utility of BE users, β₂And p₂Is a parameter that adjusts the slope of the utility function curve.

The utility function curves of the three users are shown in fig. 1.

2 method for allocating respective frequency spectrum resources of operators when virtualization is not used

When virtualization is not used, each operator allocates its own Physical Resource Block (PRB). The optimization target is as follows:

wherein, K_c,iIs the number of users of cell c of operator i, is a parameter indicating whether the nth PRB is allocated to the kth user in the cell c of the operator i, where the allocation is 1 and the unallocated is 0.

Since the above problem is a Non-deterministic Polynomial (NP) problem, an accurate solution cannot be obtained. The invention provides a PRB allocation method with lower complexity, which comprises the following specific steps:

1) considering that the utility of the HQ user is 0 when the rate requirement is not met, the PRB is first allocated to the HQ user with the utility of 0. The HQ user with utility of 0 is as followsThe values are sorted from high to low, whereinThe average SINR for a user is obtained by the following equation:

wherein N is_iIs the number of PRBs of operator i,SINR on nth PRB for kth user in cell c of operator i, P is transmit power of base station,is the channel gain, N, of the k-th user in cell c of operator i₀Is the noise power.

According toThe value sorting sequence allocates PRBs to HQ users in sequence, and all the unallocated PRBs are selected each timeThe largest PRB is allocated to the user, and the user rate is updated every time one PRB is allocated:

where B is the bandwidth of one PRB,SINR on the just allocated PRB for the user.

If the updated rate of the user does not satisfyThe user continues to be allocated PRBs. And if so, continuously repeating the steps to allocate the PRB to the rest users.

2) When the utility of all HQ users is 1, PRB allocation is started for SQ and BE users.

Each time, a user is selected that satisfies the following conditions:

i.e. PRBprb with maximum utility gain^*Assigned to user k^*And updating the rate and the utility of the user after allocation. And repeating the steps until the PRB is allocated.

3 method for sharing resources among operators by using virtualization

When virtualization is used, PRBs of all operators are concentrated into one physical base station to be shared. The physical base station allocates all PRBs to each virtual base station for each operator to use. The optimization target is NUM:

whereinIs the utility that the kth user in cell c of operator i gets when no virtualization is used. The constraint (b) is to ensure that the user does not decline in the use of virtualization. Constraint (c) guarantees utility and gain for each operatorRatio of ratio to number of PRBs shared β_iThe same is true.

The concrete method for allocating PRBs after resource sharing is as follows:

1) initializing the utility of all users to be 0, and finding the utility after allocating resources when not virtualizedSet of users K greater than 0^wv。

2) First give K^wvThe users in the set are allocated PRBs. Cyclically allocating PRBs, each cycle first findingAnd current utility U_k,c,iAnd allocating the PRB with the maximum SINR of the user in the unallocated PRB set to the user with the maximum difference. The rate and utility of the user is updated. If the updated utility is satisfiedThe user is selected from the set K^wvAnd (4) removing. If not, continuously and circularly allocating PRB according to the steps until K^wvIs empty.

3) Remaining users are allocated PRBs, the utility and gain ratios for the current operators are first calculated β_i' find proportion β of number of shared PRBs_iAnd β'_iThe operator with the greatest difference. Allocating the operator users according to the respective spectrum resources of the operators when the virtualization is not usedAllocating one PRB, updating utility and gain proportion β 'of each operator after allocation'_i. And repeating the steps until all PRBs are allocated.

The resource sharing strategy among operators in the network virtualization based on the invention has the following advantages:

1. and all operators can concentrate the frequency spectrum resources into the resource pool through network virtualization, so that the flexibility of resource sharing is improved, and the resource utilization rate is improved.

2. The utility-based resource allocation method improves the utility of the system and ensures the fairness among users at the same time.

3. The set resource sharing limiting conditions ensure that the utility of the user is not reduced during virtualization and are also improved.

4. Setting the utility and gain ratio of each operator equal to the ratio of the number of shared PRBs encourages the operators to share more spectrum resources, because the more the sharing is, the more the gain they obtain.

Drawings

Fig. 1 is a graph of utility functions for three types of service users.

Detailed Description

The implementation method of the invention is as follows:

when the virtualization is not used, each operator allocates PRBs according to the following implementation method:

1) the PRB is firstly allocated to the HQ user with the effectiveness of 0. The HQ user with utility of 0 is as followsAnd sequencing the values from high to low, and allocating PRBs to HQ users in sequence.

All unallocated PRBs are selected each timeThe largest PRB is allocated to the user, and the user rate is updated every time one PRB is allocated:

2) Allocating PRBs to SQ and BE users. Each time, a user is selected that satisfies the following conditions:

PRBprb that maximizes utility gain^*Assigned to user k^*And updating the rate and the utility of the user after allocation. And repeating the steps until the PRB is allocated.

When virtualization is used, PRBs are allocated according to the following implementation method:

3) Remaining users are allocated PRBs, the utility and gain ratios for the current operators are first calculated β_i' find proportion β of number of shared PRBs_iAnd β'_iAllocating a PRB to the operator user according to the respective spectrum resource allocation method of the operator when the operator does not use virtualization, and updating the utility and gain proportion β 'of each operator after allocation'_i. And repeating the steps until all PRBs are allocated.

Claims

1. A resource sharing method between operators based on network virtualization under various service scenes is characterized in that each operator owns three users with different services: the utility functions of three users, namely, a user with a hard service quality requirement HQ, an SQ user with a flexible service quality requirement and a BE user without a service quality requirement are defined as follows:

HQ:

SQ:

BE:

wherein r is^dIs the rate requirement of the user, r is the rate of the HQ user β₁For a parameter that can adjust the slope of the utility function curve, β₁Is that when r is equal to r^dUtility of SQ user; p is a radical of₁β is another parameter capable of adjusting the slope of the utility function curve and reflecting the flexibility of the user for the speed requirement₂And p₂Is a parameter for adjusting the slope of the utility function curve;

when network virtualization is not used, operators distribute spectrum resources for own different service users, when network virtualization is used, all the operators concentrate the spectrum resources into one physical base station for sharing, and distribute the spectrum resources for the different service users of all the operators, and meanwhile, the utility of the users is ensured not to be reduced when virtualization is used, and the utility and gain proportion of each operator is equal to the number proportion of shared PRBs;

first, respective spectrum resource allocation method for operators without using virtualization

When virtualization is not used, each operator allocates its own PRB, and the optimization target is as follows:

wherein, K_c,iIs the number of users of cell c of operator i, indicates whether the nth PRB is allocated to the kth user in the cell c of the operator iThe user parameter is 1 when distributed, and 0 when not distributed;

the PRB allocation method comprises the following specific steps:

1) allocating PRB to HQ users with the effectiveness of 0: the HQ user with utility of 0 is as followsSequencing the values from high to low, and allocating PRBs to HQ users in sequence, whereinAverage SINR for user:

wherein N is_iIs the number of PRBs of operator i,is the SINR on the nth PRB of the kth user in cell c of operator i, P is the transmit power of the base station,is the channel gain, N, of the k-th user in cell c of operator i₀Is the noise power, l is the set of all cells interfering with cell c except cell c;

where B is the bandwidth of one PRB,SINR for the user on the PRB just allocated; r is_k,c,iThe rate of the kth user in cell c of operator i;

if the updated rate of the user does not satisfyThen continuing to allocate PRBs to the user; if yes, continuously repeating the steps to allocate PRBs to the remaining users;represents a rate threshold;

2) when the utility of all HQ users is 1, starting to allocate PRBs to SQ and BE users: each time, a user is selected that satisfies the following conditions:

wherein,the rate of the kth user in the cell c of the operator i on one PRB is obtained;

PRBprb that maximizes utility gain^*Assigned to user k^*After allocation, updating the rate and the utility of the user, and repeating the steps until the PRB is allocated;

second, inter-carrier resource sharing method using virtualization

When virtualization is used, PRBs of all operators are concentrated into one physical base station to be shared, the physical base station allocates all PRBs to each virtual base station to be used by each operator, and the optimization target is NUM:

s.t(a)

(b)

(c)

whereinIs the utility obtained by the kth user in the cell c of the operator i when the virtualization is not used, the constraint condition (b) is to ensure that the user does not decrease when using the virtualization, and the constraint (c) ensures the utility and the gain of each operatorRatio of ratio to number of PRBs shared β_iThe same;

the concrete method for allocating PRBs after resource sharing is as follows:

1) initializing the utility of all users to be 0, and finding the utility after allocating resources when not virtualizedSet of users K greater than 0^wv；

2) First give K^wvThe users in the set allocate PRBs: cyclic allocation of PRBs: each cycle is first foundAnd current utility U_k,c,iAllocating the PRB with the maximum SINR of the user in the unallocated PRB set to the user with the maximum difference, updating the rate and the utility of the user, and if the updated utility meets the requirementThe user is selected from the set K^wvRemoving; if not, continuously and circularly allocating PRB according to the steps until K^wvIs empty;

3) remaining users are allocated PRBs by first calculating the utility and gain ratios β 'for the current operators'_iFinding β the ratio of the number of shared PRBs_iAnd β'_iAllocating a PRB to the operator user according to the respective spectrum resource allocation method of the operator when the operator is not used for virtualization by the operator with the largest difference, and updating the utility and gain proportion β 'of each operator after allocation'_iAnd repeating the steps until all PRBs are allocated.