ETSI TR 103 293 V1.1.1 (2015-07)

TECHNICAL REPORT
Broadband Radio Access Networks (BRAN);
Broadband Wireless Access and Backhauling
for Remote Rural Communities
2 ETSI TR 103 293 V1.1.1 (2015-07)

Reference
DTR/BRAN-0040010
Keywords
access, BWA
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3 ETSI TR 103 293 V1.1.1 (2015-07)
Contents
Intellectual Property Rights . 5
Foreword . 5
Modal verbs terminology . 5
Introduction . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definitions and abbreviations . 7
3.1 Definitions . 7
3.2 Abbreviations . 7
4 Technical scenarios and architecture . 9
4.1 Technical scenarios . 9
4.1.1 Introduction. 9
4.1.2 Traffic characteristics . 10
4.1.3 Deployment constraints . 10
4.2 Radio transport technologies . 10
4.2.1 Introduction. 10
4.2.2 WiLD (WiFi-based Long Distance) networks . 10
4.2.3 WiMAX (Worldwide Interoperability for Microwave Access) . 11
4.2.4 VSAT . 11
4.3 Architecture example . 12
4.3.1 Overview . 12
4.3.2 Network Controller . 12
4.3.3 Access Network . 13
4.3.4 Satellite backhaul scenario . 13
5 Optimization and monitoring of HNB network. 13
5.1 Introduction . 13
5.1.1 Rural deployment scenarios for HNB . 13
5.1.2 Network self-configuration procedures . 14
5.1.2.1 Bounding coverage. 14
5.1.2.2 Detection of new neighbours. 14
5.1.2.3 Frequency and primary scrambling code selection . 15
5.1.3 Long-term traffic-aware self-optimization procedures . 15
5.1.4 Criteria for switching on/off HNBs . 15
5.1.5 Dynamic cell range expansion . 16
6 Interoperability of access and transport network . 16
6.1 General . 16
6.2 Traffic offloading . 17
6.3 Network architectures and benefits of traffic offloading . 17
6.4 Implementations in 3GPP networks . 18
6.4.1 Offloading implementations complying with the 3GPP standard . 18
6.4.2 Non-standard offloading implementations: data traffic caching over satellite . 18
6.4.2.1 Introduction . 18
6.4.2.2 Content caching . 19
6.4.2.3 Content caching tests in Peru . 20
6.4.2.4 One VSAT working in a controlled environment . 20
6.4.2.5 Multiple VSATs . 21
6.5 Access network and backhaul interplay . 23
6.5.1 3GPP background . 23
6.5.2 Structure of the AN-BH interface . 24
6.5.3 Information requirement for AN algorithms . 25
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4 ETSI TR 103 293 V1.1.1 (2015-07)
7 Backhaul aware scheduling . 26
7.1 Backhaul-aware scheduling with a single HNB . 26
7.1.1 Overview . 26
7.1.2 Downlink scheduling . 26
7.1.2.1 System description and assumptions . 26
7.1.2.2 Simulation results . 27
7.1.3 Uplink scheduling . 28
7.1.3.1 System description and assumptions . 28
7.1.3.2 Simulation results . 29
7.2 Backhaul aware scheduling with multiple HNBs . 30
7.2.1 Overview . 30
7.2.2 Resource allocation (rate, power and number of codes) for multiple HNBs . 31
7.2.3 Downlink resource allocation for multiple HNBs . 31
7.2.4 Uplink resource allocation for multiple HNBs . 33
7.3 Congestion Detection and Measurement . 34
7.3.1 Introduction. 34
7.3.2 Analysis of a deployment case . 34
7.3.2.1 Delay . 34
7.3.2.2 Frame loss . 35
8 Backhaul network . 36
8.1 Multi-hop solution for backhaul of rural 3G/4G access networks . 36
9 Interface between the Access Network and the Backhaul Network . 38
9.1 Interface overview: elements and procedures involved . 38
9.1.1 Introduction. 38
9.1.2 Architecture . 38
9.2 BH state information collection . 39
9.2.1 AN algorithms requirements . 39
9.3 Formal definition of the interface . 40
9.3.1 Background . 40
9.3.2 Service provided by the protocol . 40
9.3.3 Entities involved in the protocol . 40
9.3.4 Information exchanged between entities . 40
9.3.4.1 ACK Message . 40
9.3.4.2 Information Request Message . 40
9.3.4.3 Bandwidth Availability Request Message . 40
9.3.4.4 Information Indication Message. 41
9.3.5 Message format . 41
Annex A: Simulation methodology . 42
A.1 Introduction . 42
A.2 Reference scenario and simulation parameters . 42
A.3 Power consumption model and battery dynamics . 43
A.4 Energy harvesting model . 44
A.5 Daily traffic profile . 44
History . 47

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5 ETSI TR 103 293 V1.1.1 (2015-07)
Intellectual Property Rights
IPRs essential or potentially essential to the present document may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (http://ipr.etsi.org).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Foreword
This Technical Report (TR) has been produced by ETSI Technical Committee Broadband Radio Access Networks
(BRAN).
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
Introduction
Broadband access for rural communities is one of the objectives of the European Commission. The EC FP7 project
ICT-601102 STP TUCAN3G, "Wireless technologies for isolated rural communities in developing countries based on
cellular 3G femtocell deployments" has addressed this problem and has provided a system design for deployments of
Telefonica in Peru.
The present document includes the main outcome of the project.
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6 ETSI TR 103 293 V1.1.1 (2015-07)
1 Scope
The present document describes the architecture and implementation guidance for rural BWA based on 3G femto base
stations, and a variety of terrestrial and satellite backhaul solutions. The implementation guidance includes self-
optimization of physical layer parameters and recommendations for femto-to-femto and femto-to-backhaul interaction.
Additionally, deployment examples, at least for Peru, are included.
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
http://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
reference document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] Lee K., Lee J., Yi Y., Rhee I. & Chong S.: "Mobile data offloading: how much can WiFi deliver?".
In Proceedings of the 6th International COnference (p. 26). ACM, November 2010.
[i.2] Lin Y., B. Gan, C. H. & Liang C. F.: "Reducing call routing cost for femtocells". IEEE
Transactions on Wireless Communications, pp. 2302-2309, vol. 9, no. 7, July 2010.
[i.3] Zdarsky F., A. Maeder, A. Al-Sabea, S. & Schmid S.: "Localization of data and control plane
traffic in enterprise femtocell networks". In Proceedings of the 73rd IEEE Conference on
Vehicular Technology (VTC Spring), pp. 1-5, May 2011.
[i.4] Khan M., F. Khan M. I. & Raahemifar K.: "Local IP Access (LIPA) enabled 3G and 4G femtocell
architectures". In Proceedings of the 24th IEEE Canadian Conference on Electrical and Computer
Engineering (CCECE), pp. 1049-1053, May 2011.
[i.5] Small Cell Forum Release Two documents.
NOTE: Available online at http://www.scf.io/en/index.php?utm_campaign=Release%2520Two.
[i.6] 3GPP TS 23.829: "3GPP; Technical Specification Group Services and System Aspects; Local IP
Access and Selected IP Traffic Offload (LIPA-SIPTO)" - Release 10.
[i.7] TUCAN3G D42: "Optimization and monitoring of HNB network", November 2014.
NOTE: Available at http://www.ict-tucan3g.eu/.
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7 ETSI TR 103 293 V1.1.1 (2015-07)
[i.8] TUCAN3G D41: "UMTS/HSPA network dimensioning", November 2013.
NOTE: Available at http://www.ict-tucan3g.eu/.
[i.9] TUCAN3G D51: "Technical requirements and evaluation of WiLD, WIMAX and VSAT for
backhauling rural femtocells networks", October 2013.
NOTE: Available at http://www.ict-tucan3g.eu/.
[i.10] TUCAN3G D52: "Heterogeneous transport network testbed deployed and validated in laboratory",
April 2014.
NOTE: Available at http://www.ict-tucan3g.eu/.
[i.11] Recommendation ITU-T G.114: "One way transmission time", May 2003.
[i.12] 3GPP TR 25.853: "Delay Budget within the access stratum".
[i.13] ETSI TS 125 467: "Universal Mobile Telecommunications System (UMTS); UTRAN architecture
for 3G Home Node B (HNB); Stage 2 (3GPP TS 25.467)".
[i.14] ETSI TS 123 207: "Digital cellular telecommunications system (Phase 2+); Universal Mobile
Telecommunications System (UMTS); End-to-end Quality of Service (QoS) concept and
architecture (3GPP TS 23.207 version 6.6.0 Release 6)".
[i.15] ETSI TS 125 444: "Universal Mobile Telecommunications System (UMTS); Iuh data transport
(3GPP TS 25.444 version 11.0.0 Release 11)".
[i.16] ETSI TS 133 320: "Universal Mobile Telecommunications System (UMTS); LTE; Security of
Home Node B (HNB) / Home evolved Node B (HeNB) (3GPP TS 33.320 version 12.1.0
Release 12)".
[i.17] IEEE 802.11™: "IEEE Standard for Information technology--Telecommunications and
information exchange between systems Local and metropolitan area networks--Specific
requirements Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY)
Specifications".
[i.18] IEEE 802.16™: "IEEE Standard for Air Interface for Broadband Wireless Access Systems".
[i.19] TUCAN3G D43: "Interoperability of access and transport network", April 2013.
NOTE: Available at http://www.ict-tucan3g.eu/.
3 Definitions and abbreviations
3.1 Definitions
For the purposes of the present document, the following terms and definitions apply:
heterogeneous network: network consisting of cells with different sized coverage areas, possibly overlapping and
possibly of different wireless technologies
Location Area Code (LAC): code to group cells together for circuit-switched mobility purposes
WiFi™: Technology based on IEEE 802.11 [i.17] standard.
WiMAX™: Technology based on IEEE 802.16 [i.18] standard.
3.2 Abbreviations
For the purposes of the present document, the following abbreviations apply:
ABI Access-Backhaul interface
AC Access Controller
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8 ETSI TR 103 293 V1.1.1 (2015-07)
ACK Acknowledgement
ADSL Asymetrical Digital Subscriber Line
AICH Acquisition Indicator Channel
AMC Adaptive Modulation and Coding
AN Access Network
ATM Asynchroneous Transfer Mode
AWGN Additive White Gaussian Noise
BH Backhaul
BS Base Station
BWA Broadband Wireless Access
CAPEX Capital Expenditure
CDMA Code Division Multiple Access
CPE Customer Premises Equipment
CRE Cell Range Extension
CRL Certificate Revocation List
CS Circuit Switched
DivServ Differential Services
DL Downlink
DNS Domain Name System
DSCP Differentiated Services Code Point
ECM EPS Connection Management
eNB Evolved Node B
EPC Evolved Packet Core
EPS Evolved Packet System
Er Erlang
E-UTRAN Evolved UMTS Terrestrial Radio Access Network
FCAP Frequency and Code Assignment Problem
GCP Graph Colouring Problem
GEO Geostationary Earth Orbit
GGSN Gateway GPRS Service Node
GPS Global Position System
GW Gateway
HetNet Heterogeneous Network
HMS HNB Management System
HNB Home Node B
HNB-GW Home Node B Gateway
HNBAP HNB Application Protocol
HSDPA High Speed Downlink Packet Access
IP Internet Protocol
IPsec IP security scheme
ISP Internet Service Provider
Iuh Iu home
KPI Key Performance Indicator
LAC Location Area Code
LEO Low Earth Orbit
LIPA Local IP Access
LTE Long Term Evolution
MDT Minimization Drive Tests
MEO Medium Earth Orbit
MPLS Multi Protocol Label Switching
NCell Neighbour Cell
NCL Neighbour Cell List
NOS Network Orchestration System
NP Non Polynomial
NRT Neighbour Routing Table
NTP Network Time Protocol
NWL Network Listen
OPC Optimal Power and Code allocation
OPEX Operational Expenditure
PCI Physical Cell Identity (LTE equivalent of the 3G PSC)
P-CPICH Primary Common Pilot Channel
PDP Packet Data Protocol
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9 ETSI TR 103 293 V1.1.1 (2015-07)
PF Proportional Fair
PLMN Public Land Mobile Network
PM Performance Management
PS Packet Switched
PSC Primary scrambling code
QoS Quality of Service
RAC Routing Area Code
NOTE: Code to group cells together for packet-switched mobility purposes. Routing Areas are contained within
Location Areas.
RACH Random Access Channel
RANAP Radio Access Network Application Part
RAT Radio Access Technology
RF Radio Frequency
RRC Radio Resource Control
RSSI Received Signal Strength Indication - Power level received at the antenna
RSVP Resource Reservation Protocol
RTP Real Time Protocol
RTT Round Trip delay Time
RUA RANAP User Adaption
SF Spreading Factor
SIB System Information Block
SINR Signal to Interference and Noise Ratio
SIP Session Initiated Protocol
SIPTO Selected IP Traffic Offload
SON Self-Organizing Networks
SRVCC Single Radio Voice Call Continuity
STP Specific Targeted Research Project
SW Software
TNL Transport Network Layer
TTI Time Transmission Interval
UARFCN UTRA Absolute Radio Frequency Channel Number
UE User Equipment
UL Uplink
VSAT Very Small Aperture Terminal
WCDMA Wideband Code Division Multiple Access
WiLD Long distance WiFi
4 Technical scenarios and architecture
4.1 Technical scenarios
4.1.1 Introduction
The scenarios regarded in the present document are rural areas that are far away from well-connected places. Rural
femtocells may be deployed in remote villages, and the mission of the transport network is to connect those femtocells
to the operator's core network. It is assumed that the transport network uses wireless technologies to cover distances of
tens or even hundreds of kilometres. In most of the scenarios, several hops will be required, and a common transport
infrastructure will be used to serve several villages. Several femtocells will be deployed in each village.
The use of satellite communications is considered for scenarios that need to cover extremely long distances between the
operator's core network and the access network; more details will be given below. For the rest of the cases, and even for
the connection of several femtos to a common satellite communications gateway, a combination of WiFi and WiMAX
will be explored. This does not mean that other alternatives may not be used.
Both share a common objective of proposing low-cost appropriate technologies that may help operators to provide
access to sparsely populated remote villages. In the case of the transport network, the technologies considered are
relatively cheap, may be used in non-licensed bands, have a low power consumption profile, may provide broadband
data transport services and may support QoS at a certain level. However, other professional solutions commonly used as
backhaul for small cells can be considered.
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4.1.2 Traffic characteristics
The following traffic characteristics are considered as typical:
• The backhaul connecting each femtocell to the operator's core network transports different traffic classes, such
as control traffic, telephony and data traffic as a minimum.
• The transport network assumes that different traffic classes require different QoS levels.
• It is assumed that different traffic classes receives different priorities, and a minimum QoS support would
consist of a unified end-to-end strategy in the transport network to give consistent relative priorities to the
different classes.
• It is also assumed that certain traffic classes have strict requirements in terms of throughput (maximum and
minimum), delay (maximum), jitter (maximum) and packet loss (maximum).
4.1.3 Deployment constraints
Scenarios are considered following these rules:
• Access networks that are too far for any point of presence of the operator's core network require a terrestrial
wireless transport network to connect the femtocells to a gateway (using any combination of WiLD and
WiMAX links) and a satellite link that connects the gateway to the operator's network.
• Access networks that can be deployed using terrestrial hops less than 50 km long and may be connected to the
operator's network following this rule will not require a satellite link.
• Links that are closer to towns and may be influenced by urban wireless networks operating in non-licensed
bands will use licensed frequencies or a non-licensed band that is known to be relatively free of interferences.
Links will be considered reliable under the following conditions:
• RF planning with appropriated propagation models shows availability 99,9 % of the time.
• Sites are known to be accessible and physically protected.
4.2 Radio transport technologies
4.2.1 Introduction
There are two options in transport technologies:
• Wired networks (pair cable, coaxial cable or optical fiber): with high capacity and null interference with other
networks.
• Wireless networks: with interference with other networks, with lower capacity and where the attenuation
decreases the coverage, but with lower cost of network deployment.
In rural areas the deployment of wired networks is often neither reasonable nor worthwhile. In contrast, the
features of the rural scenarios reduce the drawbacks of the wireless networks (lower capacity demand; and the
scarce presence of other networks produce a significant decrease in the interference) and increase the
advantages (the infrastructure is concentrated in selected geographical locations; no needs of maintenance or
supervision out of this locations; and the network deployment is faster and with lower cost compared with
wired networks).
Consequently, the options to offer voice and broadband data connectivity in isolated rural areas are radio
transport technologies: WiFi, WiMAX and VSAT.
4.2.2 WiLD (WiFi-based Long Distance) networks
The first WiFi standards were conceived for WLAN (Wireless Local Area Networks). The main obstacle to the
application for long distances is their MAC (Medium Access Control) protocol: CSMA/CA (Carrier Sense Multiple
Access with Collision Avoidance). This protocol is very sensitive to the propagation delay and its performance level
decreases with the distance between stations.
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11 ETSI TR 103 293 V1.1.1 (2015-07)
The PHY layer and the MAC layer establish limits in the coverage distance.
In PHY layer, the higher nominal bit rates are achieved with powerful modulations and low redundancy coding
schemes, but it only works in short distances because the received power is high. So, the bit rate decreases with the
distance. In point to point transmissions the transmitted power is the allowed maximum and the antenna gains are high.
Figure 4.1 shows that long distances can be reached only if high gain directive antennas are used, i.e. 12 dB for
omnidirectional antennas and 24 dBi for directional antennas.

Figure 4.1: Achievable distance for point to point, point to multipoint or mesh WiFi [i.9]
4.2.3 WiMAX (Worldwide Interoperability for Microwave Access)
The equipment based on IEEE 802.16 [i.18] standard is suitable to provide coverage to isolated areas with low cost and
low time of deployment. The standard provides advantages like equipment interoperability, great robustness, higher
security and the possibility to offer strict QoS support to all the communications in the network. It includes flexibility in
the frequency bands (licensed and non-licensed) and in scenarios (fixed or mobile).
4.2.4 VSAT
The objective of the satellite links in rural BWA is to serve as IP transport network between gateways and the operator's
network, mainly where the distance between gateways and operator's network is greater than 50 km. For broadband
access and IP backhauling, and for the group of services where the cellular backhauling needed for remote rural can be
considered into, it is accepted by industry that the best performance/cost solution for a satellite link is using a GEO
(Geostationary Earth Orbit) satellite.
A geostationary orbit is a particular type of geosynchronous orbit. It is a circular orbit 35 786 km above the Earth's
equator and following the direction of the Earth's rotation. A satellite in such an orbit has an orbital period equal to the
Earth's rotational period (one sidereal day), and thus appears motionless, at a fixed position in the sky, to ground
observers. The ground satellite antennas that communicate with the satellite do not have to move to track the satellite;
they are pointed permanently at the position in the sky where the satellite stays.
While it is industry accepted that GEO satellites are the best option for fixed broadband access or IP backhauling, there
are also recently industry developments and studies to offer these types of fixed services using MEO (Medium Earth
Orbit) satellites.
MEO is the region of space around the Earth, located above LEO (Low Earth Orbit, altitude of 2 000 km) and below
GEO (Geostationary Earth Orbit, altitude of 35 786 km). MEO satellites are widely used for navigation and
geodetic/space environment science. The orbital periods of MEO satellites range from about 2 hours to nearly 24 hours.
Examples of satellite systems in MEO for navigation are GPS (Global Positioning System) and Galileo.
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12 ETSI TR 103 293 29 V1.1.1 (2015-07)
As MEO satellites are not fixed in the sky ffrroom the point of view of a ground observer on Earth, theesse satellites are not
single ones and the system in composed of s seeveral ones, and named constellation. If used for fixed br broadband access or
IP backhaul, there is the need of using at leasastt two antennas with tracking devices. Each antenna moovves and tracks one
visible satellite, and a switchover of the commmmunications link from one antenna to the other is done periodicallye p as one
antenna is losing visibility of one satellite anndd the other one is locked to the next satellite in the connsstellat tion.
Using MEO satellites instead of GEO satellilittees improve IP communications performance, as the delelaay is significantly
reduced. IP communications trough a GEO s satellia te has an RTT of 600 ms to 650 ms, while with MEEO satellites it can
be reduced four or five times (estimated RTTT is 130 ms to 140 ms). This improvement is especiallyy i important when
backhauling GPRS/EDGE and 3G traffic, wwhhose performance is very sensitive to delay in the transspporto network.
Another difference between GEO and MEO s satellite systems, for broadband access and backhaulinngg,, is that GEO
satellites can provide full coverage to the Earartth (but Poles) with only 3 satellites (if strategically deplployed in the orbit,
covering 120º each one), while with MEO ssateat llites are needed more. For example, O3b will start witith 8 satellites, to be
upgraded to 12 satellites and 16 satellites.
Increase in cost of antenna subsystem to be ab able to track at least two MEO satellites, comparing to on one single antenna
pointed to a GEO satellite, makes difficult toto adopt this type of solutions for backhauling in very reemmote areas with very
low traffic needs. They will be widely used fofor backhauling between medium and big cities with hiiggh dh emand of traffic.
So for rural area deployments the best optioonn is to use a GEO satellite, as there will be more availabblle satellitee s and the
satellite terminal will be cheaper.
4.3 Architecture exammple
4.3.1 Overview
The architecture example has three main sectictions:
• Access network (composed by femtmtoocells)
• Backhaul (an IP heterogeneous traannssport network)
• Network controller that manages tthehe cells and acts as gateway with the core network
These elements and the connection scheme ca can be seen in figure 4.2.

Figure 4 4.2: Network architecture example
4.3.2 Network Controller
The Network Controller provides the followwiinng functionality:
• Access Controller (AC) that aggrreeggates the traffic carried over IP from the femtocells and provides standard
interfaces (Iu-CS and Iu-PS) to the ce core network.
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• IPsec Gateway that provides the capcapability of securing the traffic between the femtocells a annd the Access
Controller.
• NOS (Network Orchestration Sysysttem) that forms a complete 3G provisioning and managageme ent solution
with all the features needed to succecessfully deploy and operate an IP Access femtocells syyssttem.
4.3.3 Access Network
The access network will be based on femtocecells, which are inexpensive, energy efficient and self-orgrganized, and
therefore suitable for rural communicationss d deployments. The femtocells will be used in outdoor scencenarios, so they will
need to be installed on waterproof cases wiitthh external antenna. The femtocells of the access networrkk an d the network
controller will be synchronized through syncnc Over IP, using a NTP (Network Time Protocol) server fer for that purpose.
4.3.4 Satellite backhaul sc scenario
A system architecture using the satellite backckhaul in Peru is presented in figure 4.3.

Figure 4.3: Sccheme ofh the satellite backhaul scenario
In this figure the CRL server is a server fromm which Certificate Revocation Lists (CRLs) may be accccessed. CRLs are
validated by the Femtocell and Network Coontntroller Security Gateway in order to know whether eachch ca n still be trusted
(e.g. if a femtocell has been stolen, its certiffiiccate can be revoked).
Depending on the final emplacement, omnii a anntennas or directional/sectored antennas will be used t too provide coverage
to the residential area. Rather than sectoring aa single site, multiple femtocells will be preferred to inncreascr e capacity
when needed, getting the chance to increase ce coverage at the same time.
5 Optimization andand monitoring of HNB networorkk
5.1 Introduction
5.1.1 Rural deployment scscenarios for HNB
From the point of view of the access networrkk,, the different rural scenarios are grouped into three cateategories as presented
in figure 5.1:
• Small communities, are characterizeized by low traffic generation and concentrated populatiioonn and
coverage/capacity requirements canan be efficiently solved by installing one or two collocatetedd HNBs in the same
tower at high positions (see figure 5 5.1. , schema A).
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• Medium communities (see figure 5.1, schema B). The traffic density is low-medium and the population is
disperse, the access network deployment can be performed by the appropriate number of HNB in low position.
In these scenarios, a low number of deployed HNB, together with a sufficient number of licensed carrier
frequencies, allow operators to conveniently allocate carriers and guarantee inter-cell interference-free
operation. As the traffic density grows, frequency planning is needed.
• In large communities (see figure 5.1, schema C), where there is a high traffic density with hot-spots, the
combination of HNBs in high position and multiple HNBs in low positions seems the most adequate network
access architecture.
Small Communities Medium Communities
B)
A)
Large Communities
C)
Figure 5.1: Outdoor rural scenarios
The previous scenarios address the cases where HNBs are installed outdoors. In general, indoor UEs do not observe a
significant degradation of the service because the usual building in the rural scenarios studied is based in wooden walls.
However, medium and large communities could have some buildings with brick walls, like school, hospital, or town
hall. This new element demands a single HNB to provide the large traffic demand of indoor users, see figure 5.2.

Figure 5.2: Indoor rural scenarios
5.1.2 Network self-configuration procedures
5.1.2.1 Bounding coverage
In clause 5.4.1 of TUCAN3G D42 [i.7] is proposed a technique to adjust the coverage area inside of buildings by
exploiting measurement reports from UEs. The coverage area does not vary dynamically.
5.1.2.2 Detection of new neighbours
The topic of detection of new neighbours is considered in clause 5.4.2 of TUCAN3G D42 [i.7], and addresses scenarios
in figure 5.1, schema B and figure 5.1, schema C. Whilst identification of the macro-cellular layer is of both physical
engineering and practical coverage importance, the most important aspects of these are the iterative decode and detected
set reporting because these are best aligned with the goal and allow discovery of new neighbours rather than validate or
optimize ones already known to the network. Consequently, they combine to move the process of self-configuration
forward.
ETSI
15 ETSI TR 103 293 29 V1.1.1 (2015-07)
5.1.2.3 Frequency and primmara y scrambling code selection
Techniques addressed here refer to all scenariarios. Different algorithms for the frequency and PSC assssiignment problem
(FCAP) in small-cell networks are designed ad and evaluated in clause 5.4.3 of TUCAN3G D42 [i.7]. F. FCAP, which
consists in assigning one (or more) frequenccyy-code pair to each base station, is a fundamental problelemm in cellular
networks and as such, it has received considerderable attention in traditional (macro legacy cell) networorkks. The main
challenges in the design will be how to incoorporatrp e the operating conditions of the rural networks iinnttoo the design and
how to render the algorithms dynamic and a ammenable to distributed implementation.
5.1.3 Long-term traffi
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