=Paper=
{{Paper
|id=Vol-2332/paper-06-008
|storemode=property
|title=
Analytical review of schemes models for wireless multiservice networks under shared access frameworks
|pdfUrl=https://ceur-ws.org/Vol-2332/paper-06-008.pdf
|volume=Vol-2332
|authors=Ekaterina V. Markova,Anastasia A. Golskaia,Faina A. Moskaleva,Evgeny V. Mokrov,Vladimir S. Melezhik
}}
==
Analytical review of schemes models for wireless multiservice networks under shared access frameworks
==
https://ceur-ws.org/Vol-2332/paper-06-008.pdf
51
UDC 004.9
Analytical review of schemes models for wireless multiservice
networks under shared access frameworks
Ekaterina V. Markova* , Anastasia A. Golskaia* , Faina A. Moskaleva* ,
Evgeny V. Mokrov* , Vladimir S. Melezhik†‡
*
Department of Applied Probability and Informatics
Peoples’ Friendship University of Russia (RUDN University)
Miklukho-Maklaya str. 6, Moscow, 117198, Russia
†
Institute of Applied Mathematics and Communications Technology
Peoples’ Friendship University of Russia (RUDN University)
Miklukho-Maklaya str. 6, Moscow, 117198, Russia
‡
Bogoliubov Laboratory of Theoretical Physics
Joint Institute for Nuclear Research
Joliot-Curie 6, Dubna, Moscow region, 141980, Russia
Email: markova_ev@rudn.ru, golskaya_aa@rudn.ru, moskaleva_fa@rudn.ru, mokrov_ev@rudn.ru,
melezhik@theor.jinr.ru
The modern development of infocommunication technologies is closely connected with the
problem of rapid growth of the transmitted data volume in the conditions of limited radio
frequency range of mobile networks. The shortage of radio resources leads to a decrease in the
bit rate in mobile communication networks, and, consequently, degrades the level of quality
of user service, the requirements for which are defined in the telecommunication standards.
One possible solution of this problem is the use of the licensed frequency sharing system
(Licensed Shared Access, LSA) proposed by the European Telecommunication Standardization
Institute (ETSI). This system is an example of effective use of the frequency spectrum, taken
by the mobile operator for rent from the owner, who uses this spectrum periodically. The
owner has absolute priority in using this spectrum of frequencies. Setting priority is possible
with the help of various scenarios, differently influencing to the level of quality of user service.
In these conditions fundamental researches in the field of development of the most effective
scenarios of realization of a priority of the owner – mathematical modelling for shared use
schemes of radio frequencies are actual.
The second technology that solves the problem of radio resources lack is LAA - Licensed
Assisted Access. LAA is a technology that allows to increase the connection bit rate and the
bandwidth of the communication channel. LAA uses small cells for its work. By installing
small base stations with an integrated LAA system, operators can increase the transmission
rate in congested areas, for example, indoors.
Researching of such systems is aimed at the development and analysis performance measures
of Markov models describing wireless multiservice networks. Researches of such models and
current technologies used in wireless multiservice networks are carried out by the using
mathematical apparatus of the queueing theory, the teletraffic theory, and also the methods
of stochastic geometry. This will make it possible to calculate and evaluate the quality of
service (QoS) for users in wireless networks of future generations, as well as to plan various
options for the development of networks to keep previous users and attract new ones. The
paper presents an analytical review of the existing models using the considered systems and
the conducted research.
Key words and phrases: LSA, LAA, multiservice network, radio resource manage-
ment, shared frequency, frequency sharing technologies, streaming traffic, queuing system,
performance measures.
Copyright © 2018 for the individual papers by the papers’ authors. Use permitted under the CC-BY license —
https://creativecommons.org/licenses/by/4.0/. This volume is published and copyrighted by its editors.
In: K. E. Samouylov, L. A. Sevastianov, D. S. Kulyabov (eds.): Selected Papers of the 12th International Workshop on
Applied Problems in Theory of Probabilities and Mathematical Statistics (Summer Session) in the framework of the
Conference “Information and Telecommunication Technologies and Mathematical Modeling of High-Tech Systems”,
Lisbon, Portugal, October 22–27, 2018, published at http://ceur-ws.org
52 APTP+MS’2018
1. Introduction
In the modern world, portable mobile devices have become an integral part of almost
every person. Most everyone has a smartphone, tablet, laptop or other device that has
an Internet connection and uses broadband mobile services, generating more and more
traffic [1, 2]. Advanced mobile devices and connections are not only getting smarter in
their computing opportunities but are also developing due to higher-generation network
connectivity (3G, 3.5G, and 4G or LTE). Such combining device opportunities with faster,
higher bandwidth and more intelligent networks leads to wide adoption of progressive
multimedia applications that contribute to increased mobile and Wi-Fi traffic. The
increase in the number of users of mobile services leads to problems related to the
shortage of radio resources necessary to support the required level of quality of service
(QoS) and quality of experience (QoE).
Since it is expected that the amount of global traffic generated by mobile and wireless
devices will soon exceed the traffic generated by wired equipment, more efficient use of
the existing frequency spectrum is not enough to improve the situation globally. The
solution of this problem is impossible without additional frequency resources that will be
required for a number of different technologies suffering from a lack of frequency spectrum
from conventional mobile to device-to-device and multi-hop connections. Consequently,
there is an urgent need for searching and using additional resources.
To solve this problem, the largest companies such as IEEE, 3GPP and Cisco Mobile
are developing systems that can attract additional resources, or that can improve
the efficiency of using existing radio resources. The solutions offered by the companies
include, for example, the use of extremely high frequencies, the so-called millimeter waves
(mmWaves) [3], the temporary use of the band of licensed frequencies (Licensed Shared
Access system, LSA) [4], and the use system of Licensed Assisted Access (LAA) [5].
LSA technology is currently the most researched, so in this article we will consider a
description of the LSA system concept and a literary review of previous research about
this topic. A brief overview of LAA technology will also be offered.
2. Frequency resource sharing technologies
The mobile sector is developing the new generation of mobile wireless communications
networks based on cellular technologies. In a limited frequency range, the purpose of
these developments is to find solutions for more efficient, economical and rational radio
resource management. Even if the traffic growth forecasting are adjusted for the benefits
provided by the new technologies, the availability of licensed radio resources spectrum
may not be sufficient to satisfy the increased demand for mobile bandwidth until the
decade’s end.
Simplifying the use of the spectrum of unlicensed frequencies is an attempt to satisfy
the demands of the communications services market in the context of traffic growth.
An example of using an unlicensed frequency band are ubiquitous Wi-Fi networks.
The unlicensed spectrum can be an supplement to the licensed spectrum for cellular
operators to help eliminate the explosion of traffic in some scenarios, such as hotspot
areas (physical location where people may obtain Internet access, typically using Wi-Fi
technology). Technology Licensed Assisted Access offers an alternative to the operator to
use unlicensed spectrum using one radio network, thereby LAA offers new opportunities
for optimizing network efficiency.
An unlicensed spectrum can never replace the need for a more licensed spectrum
because of its inability to be used in macroelements that provide wide-area coverage
and its overall inability to provide highly reliable quality of service due to unmonitored
interference. The unlicensed spectrum has an unpredictable and rapidly changing
electromagnetic environment due to the free access of many users to it, which cannot
guarantee the high quality of transmissions. In addition, for this reason, special measures
are needed to reduce conflict situations. Thus, the unlicensed spectrum is better used
as a “licensed access” integrated into LTE, where it is considered as the carrier of the
secondary component in the carrier aggregation scenario.
Markova E. V. et al. 53
For the first time, LAA technology is introduced in 3GPP TR.36.889 Release 13 as
part of LTE Advanced (LTE-A) technology [6]. The LAA technology provides for the
aggregation of the frequency spectrum of Wi-Fi in the 5 GHz band by connecting it to
the licensed LTE spectrum. The efficiency of the Wi-Fi spectrum in busy conditions
is low, and LTE technology is able to more effectively manage resources and control
errors. The main task of LAA is to ensure efficient, uninterrupted and fair coexistence
with Wi-Fi technology. The advantage of this system is its use in any place, since
the frequency in 5 GHz is available in almost any zone. The listen-before-talk (LBT)
operating procedure, proposed 3GPP in Release 13 for LAA, is defined as a mechanism
by which an equipment makes a clear channel assessment (CCA) test before using the
channel.The CCA identifies the presence or absence of other signals on a channel in
order to determine if a channel is occupied or clear, respectively. LBT usage is one
way for fair sharing of the unlicensed spectrum and therefore it is considered to be a
key element for fair operation in the unlicensed spectrum in a single global solution
framework.
However, it is clear that the unlicensed spectrum can never match the quality of
the licensed spectrum. Therefore, the most popular ways to solve the shortage of the
frequency range are methods that allow the maximum use of licensed frequencies. A
preliminary analysis of related papers on the subject of more efficient using of the
resource spectrum showed that one of the most studied solutions to this problem in
4th generation networks (4G) and subsequent generations is the use of the LSA-system.
Licensed Shared Access, as a new additional regulatory framework, is another measure
that can improve the effectiveness use of spectrum and thus help to ease spectrum deficit
in areas where LSA may be relevant. The LSA framework enables agreed shared access
to spectrum that would otherwise be unavailable for using by mobile connection.
The LSA framework provides controlled access to the radio spectrum used by several
participants (see Fig. 1): the current owner of the resources and a limited number of
licensees (for example, cellular operators). The owner of the LSA band (shared band)
has absolute priority when deciding whether to provide access to the radio resources
of this LSA band to licensees. Licensees can access the spectrum only if the owner’s
QoS level is not disturbed. The rules governing the use of the LSA band are based on
dedicated agreement, taking into account the necessary requirements for the QoS level.
The implementation of these rules is possible using various scenarios that affect the
users QoS level served in the shared band.
Since in the LSA system the owner and the LSA licensee use the same frequency
spectrum, it is necessary to take measures to control the resulting interference between
the participants, because the absence of such phenomenon as interference has a positive
effect on the levels of QoS and QoE. Studies have shown that limiting interference on
the shared band created by licensee users is typically accomplished through two basic
scenarios – limiting the base station (BS) signal power transmitting data to devices
or interrupting service (Fig. 2). Within limit power scenario, LSA band is available,
but it is used with reduced power. All the BSs of licensee are forced to reduce the
corresponding uplink power whenever instructed. In the interruption or shutdown
scenario, LSA band is fully unavailable to the licensee. All the BSs which are have a
chance to cause interference on LSA bands are "powered off". The shutdown scenario is
to limit the power of users to zero, i.e. there is a full confiscation of the LSA band for
licensee.
Within each of these scenarios, various policies for the allocation of time or power
resource can be applied to improve the system efficiency using shared access (Fig. 3).
There are two types policies: simple policies that allow to distribute the frequency
spectrum to one type of resource and flexible policies (combinations of simple policies)
that allow to distribute several types of resource. The application of these policies makes
it possible to take into account the spatial position of network users, which becomes a
decisive factor in determining the system performance.
In addition, the achievable bit rate is the important indicator of the connection
quality and the network as a whole, as already mentioned, so should be paying special
attention to the main parameters that affect the data transmission. Therefore notice,
54 APTP+MS’2018
Financial
compensation
National
regulator
compensation
Potential
Financial
LSA
licensees
Sharing rules
and condition
Frequency
spectrum
owner
Figure 1. LSA regulatory framework: Key participants
LSA-band LSA-band LSA-band
power is available is unavailable is available
time
frequency
Limit power scenario
LSA-band LSA-band LSA-band
power is available is unavailable is available
time
frequency
Shutdown scenario
Figure 2. Scenarios of interference limitation
Markova E. V. et al. 55
power Pmax
D1 D2 D1 D2 D3
time
1 2 1 2 3
frequency Round Robin policy
power Pmax
D1 D2 D1 D2 D3 D3
time
1 2 1 2 3
frequency Full Power policy
Figure 3. Radio resource allocation policies
that the achievable bit rate depends on the bandwidth 𝜔, transmit power 𝑝, time resource
allocated for servicing in accordance with its location relative to BS 𝑑, noise power 𝑁0 ,
propagation exponent 𝜅 and is defined, according to the Shannon formula, as follows (1):
(︂ )︂
𝐺𝑝
𝑟 (𝑑, 𝑝) = 𝜔 ln 1 + (1)
𝑑𝑁0
Depending on the selected scenario of interference limitation and radio resource allocation
policy, these parameters may vary and thus achievable bit rate can take different
values (can be seen in the Fig. 2, 3).
For a better understanding of the LSA system functioning and the interaction of
its elements, the Fig. 4 shows an example of the technical implementation of the LSA
concept. The main components of this system are repository, controller and network
OA&M (Operations, Administration and Maintenance):
– LSA-Repository: This database includes the actual information on frequency
spectrum use by the owner and information about the availability of the LSA band
and the conditions of its use by the licensee.
– LSA-Controller: The LSA-Controller determine LSA spectrum availability based
on rules LSA of use and information on the owner’s use provided by the LSA-
Repository.
– Network OA&M: The OA&M translates into radio resource management commands
the availability of frequency spectrum information received from the LSA-Controller.
56 APTP+MS’2018
Available both
basic and LSA-
LSA- spectrum
Repository Only the basic
User Equipment spectrum is
available
User Equipment
LSA-
Controller The use of the
LSA spectrum is
prohibited by the
Base Station
owner
Base Station
Network
Base Station
OA&M
Base Station Basic Spectrum
LSA-Spectrum
Figure 4. An example of the LSA system architecture
Then these commands are transmitted to BSs in the LSA licensee’s network. Based
on this information, BSs enable user devices to access the LSA spectrum.
Such an implementation is not the only possible and true, but represents one of the
possible options.
3. Analysis of the current state of research LSA and LAA system
Currently, the implementation in wireless multiservice network systems shared use of
a licensed frequency spectrum LSA is still under development, therefore this subject
attracted the attention of many researchers. The literature review showed that the
number of articles devoted to simulation modeling of the LSA system is quite large,
while the analytical side of the issue is insufficiently studied.
For example, the paper [7] deals with various scenarios of network resource manage-
ment that will allow meeting the requirements of the services and applications being
developed. Special attention is paid to the issue of resource allocation for service devices
machine-to-machine interaction (M2M), which is expected to be one of the key drivers for
using shared network resources. The main idea of the work is that, unlike the currently
used frequency spectrum, most of the new spectra (about 80%) will become shared
spectra, and therefore either the models of sharing the licensed frequency spectrum LSA
or the models of opportunistic spectrum access (OSA) will be applicable to them. This
Markova E. V. et al. 57
1 5
d1 d5
d4
d3 4
d2
d6
3
2
6
d1 d 2 d3 d 4 d5 d 6
Figure 5. Accounting for the spatial position of users
once again underlines the study relevance of the proposed ETSI system LSA. However,
this paper are proposed only theoretical considerations about different scenarios of
network resource management, but actual analytical models are not provided.
The authors [8] give a detailed description of the LSA system with two separate
BS: primary and secondary. Users of the secondary BS can be served only when the
data transfer of the secondary BS does not degrade the quality of service of users of
the primary BS below a certain level, otherwise the secondary BS goes into standby
mode. To achieve this, both BS must be fully synchronized. This model provides shared
planning for only two base stations. The authors [9, 10] propose a mechanism for the
distribution of the LSA frequency spectrum among several LSA licensees using a joint
auction with a mixed graph mechanism. This scheme provides unhindered access to the
licensed sharing spectrum for various commercial operators that are not connected to
each other, and the BS are coordinated by the management organization.
The paper [11] presents a solution that uses cognitive radio technology to solve the
problem of frequency spectrum lacks providing dynamic access to the spectrum. The
model was evaluated both analytically and by means of simulation. Also in the literature,
three scenarios of limiting interference in the shared band are described in some detail:
ignoring the owner’s requests, interrupting user service [12], limiting the signal power
of the BS [13]. The analysis of two simple radio resource allocation policies, such as
policy of equal allocation of a temporary resource (Round Robin policy) and policy of
maximum employment of a bandwidth (Full Power policy) [14, 15], allows to take into
account the position of users on the plane (see Fig. 5). A combined approach using
Queuing theory and stochastic geometry was used to investigate models with simple
radio resource allocation policies, but the structure of the LSA system was not taken
into account.
In the study of technical documentation, as well as scientific articles on LAA technol-
ogy, it was found that most sources have only a descriptive part and propose simulation
models for this technology, but no mathematical models were considered. In article [16],
a new theoretical structure was proposed to quantify the performance of LAA with QoS
restrictions, and various probabilistic characteristics were derived.
58 APTP+MS’2018
4. Conclusions
Currently, rapid increasing of transmitted data volume in the cellular networks is an
important moment in the development of wireless communication technology. In recent
years, the deficit of available radio frequency spectrum has become a major obstruction
in developing today’s wireless communications technology. For provision services with
a high QoS and QoE to users is necessary the large volume of frequency resources.
Accordingly, deficit of system resources leads to degraded of bit rate in mobile networks,
and consequently reduction of QoS and QoE levels. Due to this, various methods of
using the frequency range, both licensed and unlicensed, are being actively studied.
Licensed Shared Access, as a new additional regulatory framework, is another measure
that can improve the effectiveness use of spectrum and thus help to ease spectrum deficit
in areas where LSA may be relevant. According to the literature analysis at the moment
there are no standardized solutions to choose the most effective scenarios for sharing
LSA band resources, flexible radio resource allocation policies, as well as the impact of
the spatial distribution of users on the system performance have not been studied at
all.The usage of unlicensed range resources has been studied much less. As the literature
review showed, research in this area is aimed at the implementation of LAA technology.
However, now there are no mathematical models that would allow to implement this
technology.As a task for further research, it is planned to compare performance measures
of mobile network models considering within LSA and LAA technologies depending
on various scenarios of limitation interference and different allocation policies of radio
resource.
Acknowledgments
The publication has been prepared with the support of the “RUDN University
Program 5-100” and funded by RFBR according to the research projects No. 18-37-00231
and No. 19-07-00933.
References
1. Cisco Visual Networking Index: Forecast and Methodology, 2016–2021 (Sep. 2017).
2. Ericsson, Ericsson mobility report: On the pulse of the Networked Society, Tech.
rep. (Jun. 2016).
3. T. S. Rappaport, S. Sun, R. Mayzus, H. Zhao, Y. Azar, K. G. Wang, N. Wong, J. K.
Schulz, M. Samimi, F. Gutierrez, Millimeter wave mobile communications for 5g
cellular: It will work!, IEEE access 1 (2013) 335–349lo comni (2013).
4. ETSI, Tr 103 113: Mobile broadband services in the 2300 MHz 2400 MHz band
under Licensed Shared Access regime, Tech. rep. (2013).
5. A. Mukherjee, J. Cheng, S. Falahati, H. Koorapaty, D. H. Kang, R. Karaki, L. Fal-
conetti, D. Larsson, Licensed-assisted access lte: coexistence with IEEE 802.11 and
the evolution toward 5G, IEEE Communications Magazine 54 (6) (2016) 50–57
(2016).
6. 3GPP, Tr 36.889 v13.0.0, study on licensed-assisted access to unlicensed spectrum
(release 13), Tech. rep. (2015).
7. M. M. Kassem, M. K. Marina, Future wireless spectrum below 6 ghz: A UK per-
spective, Proc. of International Symposium on Dynamic Spectrum Access Networks
(DySPAN), IEEE (59-70) (2015).
8. N. Taramas, G. C. Alexandropoulos, C. B. Papadias, Opportunistic beamforming
for secondary users in licensed shared access networks, Proc. of 6th International
Symposium on Communications, Control and Signal Processing (ISCCSP), IEEE
(2014) 526–529 (2014).
9. H. Wang, E. Dutkiewicz, G. Fang, M. D. Mueck, Framework of joint auction and
mixed graph for licensed shared access systems, Proc. of International Symposium
on Dynamic Spectrum Access Networks (DySPAN), IEEE (2015) 154–163 (2015).
Markova E. V. et al. 59
10. H. Wang, E. Dutkiewicz, G. Fang, M. D. Mueck, Spectrum sharing based on truthful
auction in licensed shared access systems, Proc. of 82nd Vehicular Technology
Conference (VTC Fall), IEEE (2015) 1–5 (2015).
11. A. Raschell‘a, L. Militano, G. Araniti, A. Orsino, A. Iera, Cognitive management
strategies for dynamic spectrum access, Handbook of Cognitive Radio (2015) 1–35
(2015).
12. V. Y. Borodakiy, K. E. Samouylov, I. A. Gudkova, D. Y. Ostrikova, A. A.
Ponomarenko-Timofeev, A. M. Turlikov, S. D. Andreev, Modeling unreliable lsa
operation in 3gpp lte cellular networks, Proc. of 6th International Congress on Ultra
Modern Telecommunications and Control Systems and Workshops (ICUMT), IEEE
(2014) 390–396 (2014).
13. I. Gudkova, K. Samouylov, D. Ostrikova, E. Mokrov, A. Ponomarenko-Timofeev,
S. Andreev, Y. Koucheryavy, Service failure and interruption probability analysis for
licensed shared access regulatory framework, Proc. of Ultra Modern Telecommuni-
cations and Control Systems and Workshops (ICUMT), 7th International Congress
on. IEEE (2015) 123–131 (2015).
14. A. Ahmadian, O. Galinina, I. Gudkova, S. Andreev, S. Shorgin, K. Samouylov, On
capturing spatial diversity of joint m2m/h2h dynamic uplink transmissions in 3gpp
lte cellular system, Lecture Notes in Computer Science 9247 (2014) 407–421 (2014).
15. O. Galinina, S. Andreev, M. Gerasimenko, Y. Koucheryavy, N. Himayat, S.-P. Yeh,
S. Talwar, Capturing spatial randomness of heterogeneous cellular/wlan deployments
with dynamic traffic, IEEE Journal on Selected Areas in Communications 32 (6)
(2014) 1083–1099 (2014).
16. Q. Cui, Y. Gu, W. Ni, R. Liu, Effective capacity of licensed-assisted access in
unlicensed spectrum for 5g: From Theory to Application, IEEE Journal on Selected
Areas in Communications 35 (8) (2017) 1754–1767 (2017).