Conference PaperPDF Available

Latency-Aware Dynamic Resource Allocation Scheme for 5G Heterogeneous Network: A Network Slicing-Multitenancy Scenario

Authors:

Figures

Content may be subject to copyright.
Latency-Aware Dynamic Resource Allocation
Scheme for 5G Heterogeneous Network: A
Network Slicing-Multitenancy Scenario
Sunday O. Oladejo
Department of Electrical Engineering
University of Cape Town
Cape Town, South Africa
oldsun002@myuct.ac.za
Olabisi E. Falowo
Department of Electrical Engineering
University of Cape Town
Cape Town, South Africa
olabisi.falowo@uct.ac.za
Abstract—In 5G Slice Networks, the multi-tenant multi-tier
heterogeneous network will be critical in meeting the Quality
of Service (QoS) requirement of the different slice use cases;
Capital Expenditure (CAPEX) and Operational Expenditure
(OPEX) reduction for mobile network operators. Hence, the 5G
slice networks should be as flexible as possible to accommodate
the different network dynamics such as of user location and
distribution, different slice use case QoS requirement, cell load,
intra-cluster interference and Mobile Virtual Network Opera-
tors (MVNOs) Service Level Agreement (SLA). Motivated by
this, this paper addresses a latency-aware dynamic resource
allocation problem for 5G Slice Networks in a multi-tenant
multi-tier heterogeneous environment, for efficient radio resource
allocation. The latency-aware dynamic resource allocation prob-
lem is formulated as a maximum utility optimisation problem.
The optimisation problem is transformed and the hierarchical
decomposition technique is adopted to reduce the complexities
in solving the optimisation problem. Furthermore, we proposed
a Genetic Algorithm (GA) Intelligent Latency-Aware Resource
Allocation scheme (GI-LARE). Our findings have been obtained
by extensive Monte Carlo numerical simulations and comparisons
were carried out with the static allocation scheme and a branch
and bound method. The genetic algorithm schemes out perform
the static scheme.
Index Terms—Multi-tenancy, Network Slicing, Heterogeneous
Network, Genetic Algorithm, Resource Allocation
I. INT ROD UC TI ON
The IMT-2020 widely regarded as the Fifth Generation (5G)
mobile networks will play a critical role in the realisation
of the Industry 4.0 revolution [1], which will reshape the
way humans and machines co-habit and live. Although this
fact is indisputable, the deployment of the 5G Networks
requires substantial financial investment and commitment by
the different mobile network players such as the Infrastructure
Providers (InP), Mobile Virtual Network Operators (MVNO),
Over-the-top players (OTP), backhaul Operators (BO). In a
bid to reduce the Capital Expenditure (CAPEX) and Operating
Expenditure (OPEX), different multi-tenancy business models
for the 5G Networks have evolved and emerged. In this work,
we modify the models in [2] [3] to suite multi-tenant network
slicing, as shown in Fig 1. In this business model, the InPs
have the ownership of the physical resources of the mobile
Fig. 1. InP-MVNO Model
network resources such as the power, cooling systems, towers
and mast, antennas, spectrum, virtualisation equipment such as
hypervisors. These resources are virtualised and allocated to
the MVNOs, who in turn provide services to their respective
slice users. In this multi-tenancy scenario, the major challenge
is how the InP dynamically, efficiently and effectively allocate
resources to the MVNOs without breaching the Service Level
Agreement (SLA) with their clientele and also meeting the
QoS requirement of different slice use cases. In this work,
without loss of generality, we consider two broad types of slice
use cases: the enhanced Mobile broadband (eMBB) and the
massive Machine-Type Communications (mMTC) slice use
cases. The eMBB slice use case is a bandwidth-hungry use
case, while the mMTCs is quite a latency or delay-dependent
use case. Unlike most works in the literature, we investigate
the concept of Network Slicing not only from the received data
rate QoS requirement; but also from the latency or delay QoS
requirement of the different slice use case. Besides, unlike the
widely investigated 2-Tier heterogeneous network environment
in the study of 5G Network Slicing, we examine the concept of
Network Slicing deployed or implemented in a hierarchical 3-
tier clustered heterogeneous network. While being modest, this
comes with its complexities. Necessarily, these are conditions
that sufficiently motivate the purpose of this paper to consider
latency-aware radio resource allocation in 5G Slice Network
in a multi-tenancy environment.
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
978-1-7281-3316-4/19/$31.00 ©2019 IEEE
A. Contributions
The contributions of this paper are as follows:
The radio resource allocation problem between the InP
and the MVNOs; the different Slice use cases; the dif-
ferent tiers of the heterogeneous networks; and between
the slice users is jointly formulated as an optimization
problem with feasible constraints in order to examine the
impact of network parameters on the network utility.
A matching game is played between the slice users and
3-tier clustered heterogeneous network in a multi-tenancy
scenario in order to associate slice users to particular
access points optimally.
Other than the data rate QoS constraints, we examine the
latency constraints are examined in the Network Slicing
concept.
A Genetic Algorithm (GA) Intelligent Latency-Aware
Resource Allocation scheme (GI-LARE) is proposed to
enhance the overall network utility. The Genetic Algo-
rithm (GA) Intelligent Latency-Aware Resource Allo-
cation scheme (GI-LARE) is compared with an exact
solution from the Spatial Branch and Bound method and
a static resource allocation scheme.
II. RE LATE D WOR KS
The authors in [4], [5] presented maximum capacity and
profit-aware resource allocation schemes for network slicing
in a multi-tenancy scenario. Slice priorities and bandwidth-
Power cost were considered, however, a static resource scheme
between the InP and MVNOs was adapted. Besides, the
latency constraints requirement of the respective slices was
not considered. Also, it is pertinent to state that a single-
tier homogeneous network was considered, which does not
entirely depict a 5G network with its complexities. In [6],
a maximum-revenue resource allocation optimisation problem
is formulated for a virtual network in a 2-tier heterogeneous
network. In solving this problem, the authors pre-allocated
radio resources to the respective base stations or access point.
In [7], a dynamic resource sharing scheme for a single-tier
homogeneous C-RANs multi-tenancy is proposed. A network
utility maximisation problem was formulated while consid-
ering the tenants’ priorities. Although the two-step proposed
sub-optimal solution improved the network utility, however,
users were not categorised based on their slice requirements.
Moreover, the authors in [8], presented a dynamic radio
resource slicing scheme for a 2-tier heterogeneous wireless
network. An alternating concave search algorithm is designed
to solve the maximum network utility optimization problem,
the 2-tier heterogeneous network due to it simplistic model
may not fully represent a 5G network environment with its
many tiers of access networks in order to meet the ever-rising
user demands. Besides the authors do not address the concept
of multi-tenancy, which is critical for CAPEX and OPEX
reduction in 5G networks. Motivated by the shortcomings
in the literature, we investigate the latency-aware dynamic
resource allocation problem in a 3-tier clustered heterogeneous
network for multi-tenancy network slicing.
Fig. 2. A 3-Tier Clustered Heterogeneous Network
III. SYS TE M MOD EL
A. General Model
In this work, the downlink of a 3-tier clustered heteroge-
neous 5G Slice Network, as illustrated in Fig. 2 is considered.
The physical resources of this network are owned, managed
and controlled by the Infrastructure Provider I, and these re-
sources (Bandwidth in this case) are allocated to the MVNOs.
Let the set of MVNOs be H. Each respective MVNO, h H is
totally independent and unaware of the other MVNOs h0 H,
its set of Slices is denoted by S={E M}. Where Eand
Mdenotes the eMBB slice and mMTC slice sets which are
explained in details in subsection III B. The hierarchical 3 -
tier network comprises of the femtocells, picocells and macro-
base stations respectively. The set of femtocells is denoted by
SC ={F PF }.F={1,2, ...f}represents the set of femto
access points located only in the coverage area of the Macro
base station, while PF ={1,2, ..., pf }denotes the set of
clustered femto in the coverage area of a picocell, p P, and
macro base station, m.Pis the set of picocells in the pico
tier. As stated earlier, the coverage area of a picocell, p, helps
to create a cluster area for a set of femtocells. The entire
heterogeneous network environment is overlaid by a macro
base station, m. For a particular MVNO, h, slice user, iis
categorized according to its requested slice use case (Eor M)
and besides, its geographical position in the heterogeneous
network.
B. Slice User Categorization
Without loss of generality, slice users are categorised into
four types.
Cat. I: Em, is the set of eMBB users belonging to MVNO,
h, in the coverage region of monly. Besides, the mMTC
slice user belonging to MVNO, h, in the coverage area
of monly is denoted as Mm.
Cat. II: The set of eMBB users in the coverage of a femto,
f F, is denoted as Efand similarly, Mffor the set of
mMTC slice users in the coverage of a femtocell f F.
Cat. III: For the pico-tier, the set of eMBB slice users in
the coverage area of a picocell p P but does not belong
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
to PF is represented as Ep. Similarly, Mpdenotes the
set of mMTC slice users which are under the coverage
area of p P and not in the clustered femto set PF.
Cat. IV: Likewise, Epf denotes the set of eMBB slice
users in one of the clustered femtocells, pf PF. For
mMTC slice users in the clustered femto, pf PF, its
set is denoted by Mpf . This categorisation is illustrated
in Fig. 2. The total number of cluster, c C is the same
as |P|.
C. Channel Model
With the downlink of a link layer model given in [9] [10],
we consider a user iwith a path loss given as:
ρi,j,h =
30 + 35 log(di,j,h),if i {Em,Mm}, j =m
35 + 35 log(di,j,h),if i {Ep,Mp}, j =p
40 + 35 log(di,j,h),if i {Ef,Epf ,Mf,Mpf }
(1)
Where di,j,h is the distance of the slice user, i, belonging
to MVNO, h, from base station (or access points), j
{m, f, p, pf }. For a user iwhich request for slice use case
{Em,Mm}and belongs to MVNO, h, and is in the coverage
of monly, its spectrum efficiency is given as:
γi,m,h = log21 + ψm,hΓi,m,h
σ2(2)
Similarly for a user i {Ef,Mf}, its spectrum efficiency
is given as:
γi,j,h = log21 + ψj,hΓi,j,h
X
k∈{F}
j6=k
ψk,hΓi,k ,h +σ2(3)
Likewise for a user i {Ep,Mp}, its spectral efficiency is
given as:
γi,j,h = log21 + ψj,hΓi,j,h
X
k∈{P}
j6=k
ψk,hΓi,k ,h +σ2(4)
For a user i {Epf ,Mpf }who subscribes to the services of
MVNO, h, its spectrum efficiency is given as:
γi,j,h = log21 + ψjc,h Γi,jc,h
X
p0c0
c6=c0X
k∈{PF 0}
j6=k
PF 6=P F0
ψk,hΓi,k ,h +σ2(5)
ψj,h is the transmit power of the access point or the base
station, j {m, F,P,PF}.
X
p0c0X
k6=j, k∈{PF 0}
ψk,hΓi,k ,h in (5) is the inter-
cluster interference of for a user iin the clustered
femto cells . The channel gain Γi,j,h, between a user
i,which belongs to a MVNO, h, and associated with base
station, j {m, F,P,PF} is given as:
Γi,j,h = 10ρi,j,h
10 (6)
D. Latency and Delay Model
For a mMTC slice user, its minimum achievable rate ui,m,h
, must be greater or equal to the effective bandwidth, uthres
h,
[9] [10] of the network source. The effective bandwidth is
a function of the delay bound violation probability, (q), the
average data packet arrival rate, λh,Mj, of mMTC slice users,
the maximum delay bound threshold, D, and the data packet
size, Lh,Mj, of the mMTC user. Therefore from [9] [10],
uthres
h=Lh,Mjlog(q)
Dln(1 log(q)
h,Mj
)(7)
In this work, Dand qare set at 100ms and 0.001, although
these values could be varied. The network parameters for
λh,Mjand λh,Ejare 5 and 20 packets per seconds. The data
packet size for the eMBB and mMTC (Lh,Ej&Lh,Mj) are
9000 bits and 2000 bits respectively.
E. Dynamic Network Slicing
In this work, the bandwidth is virtualised and pooled to a
centralised cloud server and reallocated to MVNOs. In a multi-
tenancy scenario, this is carried out in a 2-step hierarchical
method and shown in Fig. 1. The bandwidth allocated to each
MVNO in each tier t, is given as:
X
t∈{MB S,SC ,P}
βt,hB(8)
However, to fully maximise the bandwidth of the InP, the
total network slicing ratio must be equal to 1, as seen in (8):
X
h∈H X
t∈{MB S,SC ,P}
βt,h = 1 (9)
Where βt,h is the network slice ratio of MVNO, h, in tier
t, while Bis the network bandwidth. As stated earlier, βt,h
is a function of slice user distribution and location, cell load
characteristics and user QoS.
Furthermore, we consider a logarithmic utility for each cate-
gory of user specified in Section III (B).
log ui,j,h= log Bβt,h αi,j,h γi,j,h(10)
Where αi,j,h is the fraction of the bandwidth allocated to
a slice user i, belonging to a tier j {m, F,P,PF} with
bandwidth Bβt,h in MVNO h.
IV. PROBLEM FORMULATIO N
In this section, we consider the latency-aware dynamic
resource allocation problem in a 3-tier clustered heterogeneous
network in a network slicing multi-tenancy scenario. In
order to fully maximise the capacity of the network, we
formulate a joint user-association InP-MVNO resource
allocation problem in (11). The utility of each MVNO,
is the summation of the utility (or rate) of the four
categories of slice users explained in Section III (B) and
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
max X
h∈H "X
i(Em∪Mm)
log ui,m,h+X
f∈F X
i(Ef∪Mf)X
j∈{m,f}
yi,j,h log(ui,j,h)
+X
p∈P X
i(Ep∪Mp)X
j∈{m, p}
y0
i,j,h log ui,m,h+X
p∈P X
pf∈PF X
i(Epf ∪Mpf )X
j∈{m, p, pf}
y00
i,j,h log ui,m,h#
(11)
s.t.
C1: ui,m,h λh,EmLh,Emi Em,h H
C2: ui,m,h uthres
hi Mm,h H
C3: yi,j,hui,m,h uthres
h0i Mf, j {m, f },h H
C4: yi,j,hui,m,h λh,EmLh,Em0i Ef, j {m, f },h H
C5: y0
i,j,hui,m,h uthres
h0i Mp, j {m, p},h H
C6: y0
i,j,hui,m,h λh,EpLh,Ep0i Ep, j {m, p},h H
C7: y00
i,j,hui,m,h uthres
h0i Mpf , j {m, p, pf},h H
C8: y00
i,j,hui,m,h λh,Epf Lh,Epf 0i Epf , j {m, p, pf },h H
C9: X
j∈{m,f}
yi,j,h = 1 i(Ef Mf)
C10: X
j∈{m, p}
y0
i,j,h = 1 i(Ep Mp)
C11: X
j∈{m, p, pf}
y00
i,j,h = 1 i(Epf Mpf )
C12: yi,j,h {0,1} i(Ef Mf), j {m, f },h H
C13: y0
i,j,h {0,1} i(Ep Mp), j {m, p},h H
C14: y00
i,j,h {0,1} i(Epf Mpf ), j {m, p, pf},h H
C15: X
i(Em∪Mm)
αi,m,h +X
f∈F X
i(Ef∪Mf)
yi,j,hαi,m,h +X
p∈P X
i(Ep∪Mp)
y0
i,j,hαi,m,h +X
p∈P X
pf∈PF X
i(Epf ∪Mpf )
y00
i,j,hαi,m,h = 1
C16: X
f∈F X
i(Ef∪Mf)
yi,f,h αi,f,h = 1 h H
C17: X
p∈P X
i(Ep∪Mp)
y0
i,p,h αi,p,h +X
p∈P X
pf∈PF X
i(Epf ∪Mpf )
y00
i,p,hαi,p,h = 1 h H
C18: X
p∈P X
pf∈PF X
i(Epf ∪Mpf )
y00
i,pf,hαi,pf ,h = 1 h H
C19: αi,m,h (0,1) i(Em Mm Ef Mf Ep Mp Epf Mpf )
C20: αi,f,h (0,1) i(Ef Mf)
C21: αi,p,h (0,1) i(Ep Mp Epf Mpf )
C22: αi,pf,h (0,1) i(Epf Mpf )
Constraints C1, C4, C6and C8in (11) ensures that the
minimum data rate for the eMBB users is guaranteed for all
tiers ı.e for all the four categories of users in the respective
tiers. Also, C2, C3, C5and C7guarantees that the received
rate, ui,m,h, of an mMTC slice user in the different categories
is by no means less than the effective bandwidth threshold
uthres
hof the mMTC slice. Besides, yi,j,h,y0
i,j,h and y00
i,j,h are
BS-user association indicator; in this work, we consider C9,
C10 and C11 to ensure that a Cat. II slice user is either associ-
ated with a femtocell, f, or the MBS, m; Cat. III slice user is
either associated with a picocell, por MBS, m; and a Cat. IV
slice user is either associated with a clustered femtocell, pf,
or picocell p, or the MBS, mrespectively. While constraints
C12, C13 and C14 is a relaxation of constraint C9, C10 and
C11. Constraints C15, C16, C17, C18 in general highlights the
bandwidth allocation requirement of the individual slice users
in each of the tiers. C19, C20, C21 and C22 is a relaxation
of the fractional allocation indicator which must be between
0and 1ı.e a positive fractional value.
V. PROPOSED SOLUTIONS
The proposed solution to the problem is discussed in this
Section IV is a combination of different algorithms. To make
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
(11) tractable and solvable, we first simplify (10):
log Bβt,h αi,j,h γi,j,h= log Bβt,hγi,j,h+ log αi,j,h
(12)
The expression in (12) is then applied to the transformed
objective function in (11). The transformation of the objective
function (11) is shown the appendix.
A. Base Station-User Association
Using the hierarchical decomposition method in [11], firstly,
we solve the Base station-User association problem by adapt-
ing the maximum SINR association to determine the tier or
base station a user associates. A seen in Fig.2, slice users who
are in the coverage of the Macro base stations only, cannot
associate with any other tier because they are not under the
coverage of other tiers. Algorithm 1 solves the Base station-
user association in a 3-tier clustered heterogeneous network
through matching game.
B. Genetic Algorithm
We solve the transformed dynamic resource allocation prob-
lem in a clustered heterogeneous network in a multi-tenancy
scenario via Continuous Genetic Algorithm (CGA) [12], meta-
heuristic bio-inspired approach because of its ability to find
optimal solutions in a brief time. In solving (11), we restrict
the CGA search space using the constraints C1 to C22 for
optimality and fast computational convergence. We adapt
Elitism [13] to the CGA in the process of gene selection. The
probabilities of crossover, Pc, mutation, Pmand elitism Pe
play critical roles in the performance of the CGA. In this work,
Pc= 0.9,Pm= 0.9and Pe= 0.2. We choose number of
chromosomes, NChrom, to be 400; the number of variables,
NoV , is the product of |H| and the number of tiers (4). The
maximum iteration (MaxIter)is set at 50. The complexity of
the GI-LARE is given as: ONC hrom NoV MaxIter
A Spatial branch and Bound (BnB) method is adapted to
solve the maximisation problem in (11) in order to verify the
optimality of the CGA-based results. The BnB algorithm gives
a global optimal solution, and it is shown in Algorithm 3.
VI. RE SU LTS AN D DIS CU SS IO N
We consider 3-tier clustered heterogeneous network
whereby slice users subscribed to 3MVNOs over the area
of interest of 800 m radius. The femtocells, picocells and
macrocells all have coverage radius of 50 m,250 m and 800 m
respectively and transmit powers of 30 dBm,36.9 dBm,
40 dBm. The different categories of slices users are randomly
distributed across the different base stations in all the tiers,
with data packet arrival rate of 5 packets/s; 20 packets/s for
mMTC and eMBB users in the different categories. The per-
formance of the proposed algorithm is evaluated over a large
number of different simulations. A Monte-Carlo simulation
in Matlab environment is created, with a 10,000 iterations
for each simulation to validate the results. Fig. 3 show the
effect of the maximum delay bound, D, on the effective
bandwidth, uthres
h. The role of the uthres
hcan be seen in
constraints C2, C3, C5 and C6 which greatly affects the
Algorithm 1: Base Station-User Association
Data: Set Parameters
Set: ψj,h,di,j,h
if i is under the coverage of a femtocell then
if femtocell is clustered then
calculate: γi,m,h,γi,p,h ,γi,pf,h (2)(4)(5)
if γi,pf,h (γi,m,h &γi,p,h)then
y00
i,pf,h = 1
else
if γi,p,h (γi,m,h &γi,pf,h )then
y00
i,p,h = 1
else
y00
i,m,h = 1
end
end
break ;
else
calculate γi,m,h,γi,f ,h (2)(3);
if γi,f,h γi,m,h then
yi,f,h = 1
else
yi,m,h = 1
end
break ;
end
else
Calculate γi,p,h,γi,m,h (4)(5);
if γi,p,h γi,m,h then
y0
i,p,h = 1
else
y0
i,m,h = 1
end
end
Algorithm 2: Continuous Genetic Algorithm
Set Pm;Pe;Pc,MaxIter,NChrom,NoV
Step 1: Initialize the random population
Step 2: while iteration MaxIter
iteration = iteration + 1
a: using (11) det. the fitness of each chromosome
b: sort the chromosomes fitness in descending order
c: select the chromosomes wrt. to fitness
d: carry out crossover using the Pc
e: mutate the genes of chromosomes with Pm
f: perform elitism on the initial population wrt. Pe
g: select population based on (d),(e),(f)
Step 3: end while
Algorithm 3: Spatial Branch and Bound
Step 1: Initialize the upper bound, ωub, of (11)
Set the list of region Gto a single domain
Step 2: Use the least lower bound rule to choose a
subregion A G
if G=then Go to Step 6
if the lower bound in region A,ωA,lb, is infeasible
or ωA,lb ωub πthen Go to Step 5
Step 3: Obtain the upper bound, ωA,ub
if ωA,ub > ωub then Go to Step 4
else ωub := ωA,ub delete all subregions in G
if ωA,ub ωA,lb πthen Go to step 5
Step 4: Partition A into subregions Aleft andArig ht
Step 5: Delete Afrom Gand Go to Step 2
Step 6: End Search
if ωub =then problem is infeasible
else ωub is the global optimal of the solution
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
received rate of the mMTC slice users. We observe that as
the maximum delay bound increases, the threshold decreases
which is in tandem with (7). Fig.4. presents the relationship
between the average arrival rate of slice users and the slicing
ratio of the network. Fig. 4 clearly shows that, for the different
MVNOs, the slicing ratio of the dynamic GI-LARE algorithm
varies with the varying network parameters rather than the
Static slicing algorithm for the different average arrival rate
examined. Fig 4. shows that the dynamic GI-LARE algorithm
ensures fairness to the different tiers while at the same time
maximising the network utility.
Fig. 3. The effect of the maximum delay bound on the effective bandwidth
threshold
Fig. 4. Impact of slice user average arrival rate λon the Slicing Ratio, βt,h
for respective MVNOs
Fig.5 shows the impact of the average arrival rate of the
slice users on the total network utility. In Fig. 5 we assume
the slice users in the different categories have the same average
arrival rate. It can be observed that as the average arrival
increases, the total network utility improves. Besides, the
Dynamic GI-LARE algorithm performs quite better than the
static-allocation algorithm. The Dynamic GI-LARE scheme
performance is quite the same as the BnB approach, which
gives a globally optimal solution.
Fig. 5. Effect of the slice user average arrival rate on the total utility of the
network
Fig. 6 presents the impact of the eMBB data packet size on
the network utility. It can be observed that as the packet size
increases the net utility increases until about 4000 bits and
then a dip occurs in the net utility. This can be ascribed to the
bandwidth limitation of the network. However, the dynamic
GI-LARE approach outperforms the static resource allocation.
Fig. 6. Effect of the eMBB data packet size on the total network utility
VII. CO NC LU SI ON
In this paper, a Genetic Algorithm (GA) Intelligent Latency-
Aware Resource Allocation scheme (GI-LARE) that explicitly
takes into consideration the latency and data rate constraints
slices in a multi-tenant heterogeneous is proposed. The opti-
mization problem is transformed and solved using the hierar-
chical decomposition method. The slice users are associated
with base stations in different tiers and, the bandwidth resource
allocation problem is solved using GA, BnB and a static
approach. With the aid of Monte-Carlo simulations, extensive
numerical analysis was performed showing different scenarios,
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
and the dynamic GI-LARE scheme far outperforms the static
approach.
VIII. ACK NOWLEDGEMENT
The authors gratefully acknowledge the support of the
National Research Foundation (NRF) and Telkom Centre of
Excellence (COE) in Broadband Networks, South Africa.
REF ER EN CE S
[1] N. Dao, Y. Lee, S. Cho, E. Kim, K. Chung, and C. Keum, “Multi-
tier multi-access edge computing: The role for the fourth industrial
revolution, in 2017 International Conference on Information and Com-
munication Technology Convergence (ICTC), Oct 2017, pp. 1280–1282.
[2] A. Belbekkouche, M. M. Hasan, and A. Karmouch, “Resource discovery
and allocation in network virtualization,” IEEE Communications Surveys
Tutorials, vol. 14, no. 4, pp. 1114–1128, Fourth 2012.
[3] S. Kukli´
nski, L. Tomaszewski, K. Kozłowski, and S. Pietrzyk, “Business
models of network slicing,” in 2018 9th International Conference on the
Network of the Future (NOF), Nov 2018, pp. 39–43.
[4] S. O. Oladejo and O. E. Falowo, “5g network slicing: A multi-tenancy
scenario,” in 2017 Global Wireless Summit (GWS), Oct 2017, pp. 88–92.
[5] ——, “Profit-aware resource allocation for 5g sliced networks,” in 2018
European Conference on Networks and Communications (EuCNC), June
2018, pp. 43–9.
[6] C. Liang, F. R. Yu, H. Yao, and Z. Han, “Virtual resource allocation
in information-centric wireless networks with virtualization,” IEEE
Transactions on Vehicular Technology, vol. 65, no. 12, pp. 9902–9914,
Dec 2016.
[7] Z. Jian, W. Muqing, M. Ruiqiang, and W. Xiusheng, “Dynamic resource
sharing scheme across network slicing for multi-tenant c-rans,” in
2018 IEEE/CIC International Conference on Communications in China
(ICCC Workshops), Aug 2018, pp. 172–177.
[8] Q. Ye, W. Zhuang, S. Zhang, A. Jin, X. Shen, and X. Li, “Dynamic radio
resource slicing for a two-tier heterogeneous wireless network,” IEEE
Transactions on Vehicular Technology, vol. 67, no. 10, pp. 9896–9910,
Oct 2018.
[9] Dapeng Wu and R. Negi, “Effective capacity: a wireless link model
for support of quality of service,” IEEE Transactions on Wireless
Communications, vol. 2, no. 4, pp. 630–643, July 2003.
[10] ——, “Effective capacity-based quality of service measures for wireless
networks,” in First International Conference on Broadband Networks,
Oct 2004, pp. 527–536.
[11] D. P. Palomar and M. Chiang, “A Tutorial on Decomposition Methods
for Network Utility Maximazation,” IEEE Journal on Sel. Areas in
Comms. (JSAC), vol. 24, no. 8, pp. 1439–1451, 2006.
[12] S. Mirjalili, Evolutionary Algorithms and Neural Networks. Reading,
Massachusetts: Springer International Publishing, 2018.
[13] H. Du, Z. Wang, W. Zhan, and J. Guo, “Elitism and distance strategy
for selection of evolutionary algorithms, IEEE Access, vol. 6, August
2018.
2019 International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)
... A widely agreed-upon solution to the SVM's hyperparameter conundrum is the use of metaheuristics, owing to their simplicity and ease of implementation, local optima avoidance, no need for gradient-based information, and flexibility [8]. Thanks to these advantages, metaheuristics have found applications in several fields of endeavors such as engineering design, production, resource allocation in wireless networks, and scheduling [9][10][11][12][13][14][15]. Fig. 36.1 illustrates some of these applications. ...
... The Levy distribution is given by: where s denotes the Levy flight's step size. Therefore, from [22], s is given by: 13) where N represents the Gaussian distribution. To this end, the spiral updating process of the WOA is improved by the MSWOA by including the Levy distribution as follows: ...
Chapter
Full-text available
Handbook of Whale Optimization Algorithm: Variants, Improvements, Hydrids, and Applications
... • AT & T North America topology from [11] is considered as a multi-layered graph with shared-SFCs distributed over the entire region and exchanging information. The demand-based user traffic analysis is modelled following the MIP. ...
... An extensive solution leveraging Monte Carlo simulation is done using a genetic algorithm. Their findings aim to minimize the misuse of available resources within a resource-constrained environment [11]. Dynamic resource allocation is addressed using a unique PDRA (Priority-Based Dynamic Resource Allocation) Scheme in [14]. ...
Article
Full-text available
Network Slicing (NS) technique is comprehensively reshaping the next-generation communication networks (e.g. 5G, 6G). Software-Defined Networking (SDN) and Network Functions Virtualization (NFV) predominantly control the flow of service functions on NS to incorporate versatile applications as per user demands. In the virtualized-Software Defined Networking vSDN environment, a chain of well-defined virtual network functions (VNFs) are installed on Service Function Chains (SFCs) by multiple Internet Service Providers (ISPs) concurrently. Generation, allocation, re-allocation, release and destroying associative VNFs on SFC is an extremely difficult task while keeping high selection accuracy. Towards solving this fundamental issue, in this work, we have proposed a multi-layered SFC formation for adaptive VNF allocation on dynamic slices. We have formulated an ILP to address the VNF-EAP (VNF-Embedding and Allocation Problem) over real network topology (AT&T Topology). Leveraging machine learning techniques we have shown an intelligent VNF selection mechanism to optimize resource utilization. The performance evaluation shows remarkable efficiency on ML-driven dynamic VNF selections over static allocations on SFCs by halving resource usage. Further, we have also studied a VNF typecasting technique for service backup on outage slices in the field of disaster management activities.
Conference Paper
5G ultra-reliable low-latency communication (uRLLC) requires extremely low latency and high reliability to serve safety-critical user ends (UEs) and applications. To fulfill those requirements, many uRLLC-related tasks are simplified for Quality of Service (QoS) analysis. Commonly Poisson or Bernoulli distributions are assumed for the incoming traffic. However, both distributions can only roughly present the characteristics of most communication traffic. On the other hand, the analysis of QoS according to predictions of traffic also requires further research. In this work, we consider the existence of a predictor for the incoming traffic and take the cumulative density function (CDF) of prediction errors into uRLLC’s QoS discussions. Furthermore, we consider a typical uRLLC resource allocation task and apply model predictive control (MPC) by converting the QoS into constraints of an optimization problem. The simulations shows that MPC can provide good performance with the prediction module, enhancing a robust operation and mitigating the stochastic effects of environmental conditions.
Chapter
In recent years, cloud-based smartphone applications like augmented reality (AR), facial recognition, and object detection have gained popularity because the remote execution of cloud computing may create significant latency and increase back-haul bandwidth usage. Addressing these issues the research seeks to employ Deep Deterministic Policy Gradient (DDPG), type of Reinforcement Learning (RL) and enhance it by prioritizing the experiences stored int the replay buffer to allocate resources for mobile users in an edge computing environment. Edge computing, which proceeds storage and processing resources near the mobile users, can increase reaction times and relieve back-haul congestion by taking into account the computational resources, migration bandwidth, and offloading targets.
Chapter
Access to the Internet is growing exponentially due to its ease of usability, flexibility, and lowering data plans. The diverse network service requirements encourage mobile operators to look for mechanisms that facilitate efficient use of network infrastructure, so that it can reduce the operational and expenditure costs. Use cases like the video streaming services requires high bandwidth, autonomous driving and remote medical surgery requires low latency, and various IoT applications work with low bandwidth to cater to the users needs. We simulate the RAN slicing using an emulator called eXP-RAN which effectively manages the allocation of different network resources to the created slices. The infrastructure, slicing, and service layers are the three distinct layers in the proposed system architecture. The isolation and abstraction of the network resources is also applied to the created slices by this emulator.
Article
Full-text available
In this study, the specific absorption rate (SAR) and exposure index (EI) of access points (APs) and user equipment (UEs) in fourth-generation (4G) and fifth-generation (5G) wireless technologies are examined with regard to the effects of exposure to radiofrequency (RF) electromagnetic fields (EMF) radiation and the implications of their reduction. We characterize the EI using a classical mathematical method while considering the power density, the SAR, the electric field strength, and the tissue's density and conductivity. As such, a novel exposure-index open-loop power control algorithm is proposed to evaluate the realistic RF-EMF radiation exposure on human users from both the downlink (DL) and uplink (UL) communication devices. To solve an EI minimization problem using the open-loop power control algorithm, we formulate it in the form of a mixed-integer nonlinear programming (MINLP) problem. As the energy capacity (i.e., power density) in wireless networks determines the radiation exposure (SAR and EI), it minimizes the EI by controlling and managing the transmitted and received powers under the restrictions of Quality of Service (QoS), interference, and power, while ensuring the users' QoS requirements are met. Our proposed scheme is numerically compared to other heuristic algorithms and exposure limits established by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) and other similar organizations. Lastly, we compare the emissions from 4G and 5G networks to the emissions from UL and DL transmissions. Our simulation findings indicate that our proposed technique is a good alternative. Our assessment, in terms of numerical results and evaluation, also verifies that the exposures are bearable, fall within the recommended limits, and are minimized without impairing the users' QoS.
Article
Full-text available
Owing to the no free lunch theorem, no single optimisation algorithm can solve all optimisation problems accurately, so new optimisation techniques are required. In this paper, a novel metaheuristic called the deep sleep optimiser (DSO) is proposed. The deep sleep optimiser mimics the sleeping patterns of humans to solve optimisation problems. The DSO is modelled on the rise and fall of homeostatic pressure during the human sleep process. Human sleep is often modelled on the four sleep stages and the deep sleep stage is employed in this work. The mathematical model of sleep homeostatic pressure is employed to simulate and determine the deep sleep state. The performance of DSO is demonstrated by employing 23 traditional functions (i.e., unimodal, multimodal, and fixed multi-modal functions), six composite functions, three engineering design problems, two knapsack problems, and six widely known travelling salesman’s problems. Additionally, the performance is evaluated in terms of accuracy, computational running time, the Wilcoxon rank sum, and the Friedman test. Lastly, the DSO is compared with 11 other metaheuristics, including GA, PSO, TLBO, and GWO. The DSO fares comparably well and, in most instances, it outperforms other metaheuristics.
Article
Full-text available
Recently reconfigurable intelligent surface (RIS) has attracted great attention because it can create a smart wireless environment. Hence it can enhance the capacity and coverage of the wireless network significantly. A thorough review of RISs has been presented in this paper focusing on the hardware aspect of the RIS. Beyond-5G/6G communication will have a smart propagation environment, where RIS can be used for such communications. RIS consists of various small unit cells. The unit cells should have some tunning mechanism so that the incoming waves can be reflected or transmitted in the desired direction. It is possible to tune the impedance of the unit cells using PIN diodes, varactor didoes, microelectromechanical (MEMS), thermal, and other ways. In this paper, initially, the background of RIS has been discussed where RIS is going to play a significant role in beyond-5G/6G communications. We have also added the theoretical background of RIS and motivations to writing this paper. After that several published papers in the literature have been presented so that the readers can get an overall idea about the RIS and its hardware. Hence, this paper will be very useful for practitioner engineers and researchers. RISs have been presented in various tables and various parameters have been presented. We have discussed challenges and solutions for the hardware of the RIS design. We have also discussed potential research and research gap that can be explored in the future. Lastly, we have added a conclusion for this review paper.
Article
Full-text available
Evolutionary algorithms have been applied successfully in many fields. However, evolutionary algorithms cannot find an optimal solution on many occasions because the balance between exploration and exploitation is lost in runs. So far, tricking the balance is an important research topic in the field of evolutionary computation. Elitism strategy is a typical scheme applied in selection for the above purpose and can be widely used in different evolutionary algorithms. In this paper, we propose elitism and distance strategy based on elitism strategy. According to our strategy, elites are still kept in selection for reducing genetic drift. Meanwhile, the individual among candidates for selection having the longest distance to each elite is also kept for maintaining diversity. We carry out experiments based on not only a genetic algorithm for traveling salesman problem but also two differential evolution algorithms, DE/rand/2/bin and CoBiDE. Experimental results show that adding our strategy in all generations can significantly improve solutions of the genetic algorithm for traveling salesman problem. Moreover, calling our strategy at a low probability can significantly improve solutions of DE/rand/2/bin, while calling the strategy based on our proposed adaptive scheme can statistically improve solutions of CoBiDE, a state-of-the-art differential evolution algorithm. OAPA
Article
Full-text available
In this paper, a dynamic radio resource slicing framework is presented for a two-tier heterogeneous wireless network (HetNet). Through software-defined networking (SDN)-enabled wireless network function virtualization (NFV), radio spectrum resources of heterogeneous wireless networks are partitioned into different bandwidth slices for different base stations (BSs). This framework facilitates spectrum sharing among heterogeneous BSs and achieves differentiated quality-of-service (QoS) provisioning for data service and machine-to-machine (M2M) service in the presence of network load dynamics. To determine the set of optimal bandwidth slicing ratios and optimal BS-device association patterns, a network utility maximization problem is formulated with the consideration of different traffic statistics and QoS requirements, location distribution for end devices, varying device locations, load conditions in each cell, and inter-cell interference. For tractability, the optimization problem is transformed to a biconcave maximization problem. An alternative concave search (ACS) algorithm is then designed to solve for a set of partial optimal solutions. Simulation results verify the convergence property and display low complexity of the ACS algorithm. It is demonstrated that the proposed radio resource slicing framework outperforms the two other resource slicing schemes in terms of low communication overhead, high spectrum utilization, and high aggregate network utility. IEEE
Article
Wireless network virtualization and information-centric networking (ICN) are two promising technologies in next-generation wireless networks. Traditionally, these two technologies have been addressed separately. In this paper, we show that jointly considering wireless network virtualization and ICN is necessary. Specifically, we propose an information-centric wireless network virtualization framework for enabling wireless network virtualization and ICN. Then, we formulate the virtual resource allocation and in-network caching strategy as an optimization problem, considering not only the revenue earned by serving the end users but the cost-of-leasing infrastructure as well. In addition, with recent advances in distributed convex optimization, we develop an efficient alternating direction method of multipliers (ADMM)-based distributed virtual resource allocation and in-network caching scheme. Simulation results are presented to show the effectiveness of the proposed scheme.
Article
Network virtualization is considered an important potential solution to the gradual ossification of the Internet. In a network virtualization environment, a set of virtual networks share the resources of a common physical network although each virtual network is isolated from others. Benefits include increased flexibility, diversity, security and manageability. Resource discovery and allocation are fundamental steps in the process of creating new virtual networks. This paper surveys previous work on, and the present status of, resource discovery and allocation in network virtualization. We also describe challenges and suggest future directions for this area of research.
Conference Paper
An important objective of next-generation wireless networks is to provide quality of service (QoS) guarantees. This requires a simple and efficient wireless channel model that can easily translate into connection-level QoS measures such as data rate, delay, and delay-violation probability. To achieve this, in D. Wu and R. Negi (July 2003), we developed a link-layer channel model termed effective capacity, for the setting of a single hop, constant-bit-rate arrivals, fluid traffic, and wireless channels with negligible propagation delay. In this paper, we apply the effective capacity technique to deriving QoS measures for more general situations, namely: 1) networks with multiple wireless links, 2) variable-bit-rate sources, 3) packetized traffic, and 4) wireless channels with non-negligible propagation delay.