Content uploaded by Seppo Yrjola
Author content
All content in this area was uploaded by Seppo Yrjola on Jul 25, 2018
Content may be subject to copyright.
Blockchain Network Slice Broker in 5G
Slice Leasing in Factory of the Future Use Case
Jere Backman
VTT Technical Research Centre of Finland Ltd.
Oulu, Finland
jere.backman@vtt.fi
Kristiina Valtanen
VTT Technical Research Centre of Finland Ltd.
Oulu, Finland
kristiina.valtanen@vtt.fi
Seppo Yrjölä
Nokia
Oulu, Finland
seppo.yrjola@nokia.com
Olli Mämmelä
VTT Technical Research Centre of Finland Ltd.
Oulu, Finland
olli.mammela@vtt.fi
Abstract—5G Network Slice Broker concept aims to enable
mobile virtual network operators, over-the-top providers, and
industry vertical market players to request and lease resources
from infrastructure providers dynamically according to needs. In
the future digital factory, the leasing of resources could also
happen autonomously by manufacturing equipment. This paper
presents Blockchain Slice Leasing Ledger Concept and analysis
of its applicability in the Factory of the Future. The novel concept
utilizes 5G Network Slice Broker in a Blockchain to reduce
service creation time and enable manufacturing equipment
autonomously and dynamically acquire the slice needed for more
efficient operations.
Keywords—blockchain; manufacturing; network management,
network slicing, 5G, IIoT
I.
I
NTRODUCTION
The next 5th Generation mobile networks (5G) will
revolutionize the way network services will be provided and
consumed. Wide variety of users, machines, industries, public
services and organizations will each have their special
demands, and the 5G network is expected to fulfill these needs.
Furthermore, 5G could be the enabler for new innovative
business opportunities and use cases, and lower the barrier to
collaborate across domains. E.g., for the industrial control and
factory automation 5G can enable fully automated and flexible
production and manufacturing systems consisting of sub-
processes and subassemblies from several stakeholders.
Consequently, this shift to more on-demand and decentralized
network services will require changes in the network’s
architecture especially in the management and orchestration
level. [1]
At present, one key component of the 5G network
management architecture under intensive research is network
slicing that is intended to enable operators to slice a single
physical network into multiple virtual networks optimized
according to specific services and business goals [2]. This way,
any special network service request, e.g., low-latency control
of a manufacturing robot, can be served combining available
Virtualized Network Functions (VNF) as network slices with
certified service levels. However, this approach reveals the
need of brand new part in the 5G network architecture: 5G
network slice broker which can enable mobile virtual network
operators (MVNO), over-the-top providers (OTT), and industry
vertical market players to request and lease resources from
infrastructure providers (InP) dynamically according to needs
[3].
In our study, we build on the top of the slice broker concept
introduced by Samnadis [3] through researching how
Blockchain technology (BC) can further facilitate the operation
of the network slice broker. The BC, described to be potentially
as disruptive as 5G, has already raised wide interest, e.g., in
financial and energy sectors as well as logistics and supply
chains because it provides novel trust mechanisms which in
turn are prerequisite for forming efficient collaborative and
networked business ecosystems [4]. In multi-actor
trading/leasing systems absence of trust, need for automation
and unwillingness to manage centralized systems, drive
solutions towards decentralized transaction and data
management like BCs [5]. Furthermore, interesting scenarios
have been presented how IoT and BC could be integrated in
order to promote the machine-to-machine interaction [6].
However, according to the authors’ best knowledge, the
application of BC to the management of virtualized 5G
network resources and slices has not yet been studied
elsewhere.
In the 3rd Generation Partnership Project’s (3GPP) study
on management and orchestration of network slicing for next
generation network, it was emphasized that multi-operator slice
creation requires the establishment of mutual trust relationships
between the operators [7]. We see that the features of BC could
inherently support many processes in the upper layer of the 5G
network slice management, and in this paper, we will outline
how blockchain based system could work as a broker platform
for virtualized network functions in 5G. The research questions
are: 1) What kind of tasks BC could handle?, and 2) What are
the advances compared to the more traditional approaches and
what kind of limitations possibly exist? In this study, we will
978-1-5386-3197-3/17/$31.00 ©2017 IEEE
use industrial control and factory automation “Factory of the
Future” as a use case example, and accordingly consider how
BC based slice broker could automatically handle network
service requests, and what kind of effects this kind of system
conceivably would have on the factory’s business ecosystem.
In this paper BC Slice Leasing Ledger Concept and
analysis of its applicability in the Factory of the Future is
presented. The novel concept utilizes 5G Network Slice Broker
in a BC to enable manufacturing equipment autonomously and
dynamically acquire the slice needed for more efficient
operations.
The paper is organized as follows. At first, Factory of the
Future network service requirements, 5G Network & Slicing
and BC enabling technologies are introduced. In Chapter III,
BC Slice Leasing Ledger Concept is presented. The concept’s
applicability to the factory of the future is analyzed in Chapter
IV. Finally, conclusions and further work are discussed.
II. T
ECHNOLOGY
E
NABLERS
Following chapters provide background relating the Factory
of the Future and its requirements for network services, next
generation 5G network, and BC as a distributed ledger.
A. Factory of the Future and New Requirements for Network
Services
The next generation of mobile broadband (MBB) networks
aims to integrate vertical sectors’ services into its architectures
and ecosystem. New services and business models coming
from vertical industries imply new demanding requirements,
new actors, and new ways of building and managing wireless
networks [8]. Current technologies lack capabilities related to
wireless performance, managing heterogeneity, privacy and
security, leverage of internet technologies, and flexible network
and service co-management [9]. Moreover, transformation
towards new data driven business models for local small and
medium size firms and global players exploiting cloudification,
network virtualization and as-a-Service (aaS) “servitization”
open new opportunities with need for capabilities. New
business models could, e.g., be built around process-aaS,
robot/machine-aaS, maintenance-aaS, or virtual network-aaS.
Vertical service integration of networked factory allows for an
optimized and more dynamic usage of resources, and calls for
linkage of manufacturing processes performed by multiple
systems and providers inside the factory boundaries. This sets
stringent requirements for Service Level Agreement (SLA)
processes, workflow integration, standardized interfaces, and
networked services for security, trust and data analytics.
Fundamentally, the aim of the industrial communication is
to monitor and control real-world actions and conditions of the
specific physical equipment, while the primary function of
MBB is data transfer and processing, as depicted in Fig. 1.
Industrial automation has a wide range of use cases with a
unique set of communication requirements, particularly
latency, reliability, availability, and throughput. Furthermore,
the communication system deployments of the use cases have
several differentiating characteristics: propagation and channel
conditions can have severe fading and multipath effects, there’s
no determinism for channel access, and extreme latency and
reliability requirements needed at the same time. High device
density, relatively small packet sizes with very short inter
arrival times, and high data rates further increase the
requirements for the future factory communications. These
high-quality networks are typically geographically confined in
area, serve heterogeneous professional applications requiring
high predictable levels of service guarantee, and may require
own network control and operation functions due to specific
security standards and privacy requirements. Moreover,
dependent on the use case there can be a need to support long
distance communication, e.g., in process automation or
utilities. On the other hand, in the manufacturing and logistics
use cases, distances are typically small, and a high degree of
flexibility is needed. Next, typical industrial automation use
cases are described in more detail.
Discrete digital factory involves sourcing, producing,
assembling, testing and distributing products in many discrete
steps. Manufacturing has the most stringent requirements on
latency and reliability. In discrete manufacturing, machine
tools, robots, sensors and programmable logic controllers
typically exchange small sized data packets with very short
intervals.
Control comprises the speed, acceleration, angle or a hybrid
control of the discrete manufacturing processes, e.g., electric
motor and servo control. Motion control sets very high
reliability and extremely low latency requirements.
Conditions of the machines and processes are continuously
monitored through measuring and analyzing certain physical
parameters such as temperatures, humidity, vibration,
acceleration and position. In a case, set threshold values are
exceeded, a concrete action is initiated by the controller.
Continuous condition monitoring has specific requirements for
determinism, reliability, redundancy, cyber security, and
functional safety. Process applications need deterministic
behavior and therefore target low latencies and high reliability.
Pure sensor data capturing, e.g., for the predictive maintenance
of the machines typically have more relaxed requirements on
the latency and reliability.
Augmented reality (AR) is a computer-assisted extension of
reality. In the first phase, a visual stimulus is projected onto
glasses to augment the reality. AR can be used, e.g., for local
and remote training, to perform maintenance and repair work,
support assembly, to control robots, and in the future to enable
collaborative robotics scenario, in which robots work side-by-
side with humans. High quality videos or images augmented
and synchronized with the reality need relatively large packet
size, high data rates, high reliability and low latency. In the
factory of the future, everything in the physical factory floor
has a digital twin in the cloud. The cyber representation of the
factory needs to be protected with mission critical actions being
shielded for non-authorized parties.
Logistics consist Automated Guided Vehicles (AGVs),
drones and static systems such as cranes and hoists. AGVs can
be mobile robots, small logistics vehicles or mobile working
platforms which transport materials, sub-assemblies and
products inside the factory and warehouses. In addition to
obvious mobility requirements, low latency and extreme high
reliability needs to be ensured. The static case of cranes and
hoists, are an essential part of future wireless factory replacing
cabling.
Safety cross all above discussed use cases securing a certain
safety integrity level [10]. Safety has been extended from
protecting humans to cover machines, their environment, and
production processes. E.g., radars, laser scanners, wearables or
protective skins can be used to protect a certain area or a
machine. The communication requirements are marginally
lower compared to manufacturing.
On the basis of detailed use case specific requirements, e.g.
[11],[12],[13],[14] and [7], comparison of industrial and MBB
communications requirements can be summarized, in Fig. 1.
Fig. 1. Comparison of the typical new requirements of Industrial
Communications and Mobile Broadband use cases.
B. Next Generation 5G Network and Network Slicing
The upcoming 5G will evolve from the current ecosystem
to support heterogeneous high-speed access technologies and
have built-in support for various novel services and
applications, users and devices. Furthermore, it should be able
to provide much greater throughput, lower latency, ultra-high
reliability, higher connectivity density, improved energy
consumption, greater capacity, and higher mobility range for
enhanced MBB users as well as for enterprises and verticals
with such as finance, real estate, health, utilities, industrial
automation and government [1].
In addition to new 5G radio (5G-NR), key concepts under
research are software defined networking (SDN), network
function virtualization (NFV), and network slicing. These new
features enable that the logical network components are
decoupled from the hardware, and it is possible to create virtual
networks. In network slicing, the nodes and communication
related to particular applications are service specific and
isolated from each other. The behavior and communication of
network devices and flows are controlled with SDN software
that operates independently from the network hardware. [2]
Moreover, the low latency, security and privacy solutions
could involve placing network functions closer at the edge of
the access network. This includes introducing the framework of
mobile edge cloud to meet these critical and crucial
requirements. 5G should be also be backwards compatible, i.e.,
an efficient interworking between 5G and LTE should be
provided. [2]
To accommodate the variety of different use cases and
services and exploit the benefits of a common network
infrastructure, the concept of network slicing has been
proposed. A single network slice can be defined as a logical
instantiation of a physical network with all the needed
functionalities that is needed for running a given service.
Network slices can support a communication service for a
particular connection type. A slice provides all necessary
functionality for a service and basic isolation. All other
functionality is avoided, which thus minimizes the internal
complexity of a slice. Network slices can be considered more
as networks on-demand, which will be created, deployed and
removed dynamically. Furthermore, slices are isolated and
restricted to the assigned resources. [8]
The essential building blocks to enable network slicing are
SDN and NFV technologies. SDN separates the control and
data planes. The separation enables faster provisioning and
configuration of network connections. SDN enables network
administrators to program the behavior of traffic and the
network in a centralized way. Without SDN each of network
hardware should be accessed independently. The decoupling of
system’s control and data plane thus simplifies networking as
well as the deployment of new protocols and applications. It
could also increase flexibility and efficiency of the network.
[15]
By using NFV, it is possible to create network functions or
mobile network entities on-demand, place them on the most
suitable location using the most appropriate amount of
resources [16]. Examples of network functions and mobile
network entities include Packet Data Network Gateway
(PGW), Serving Gateway (SGW), Mobility Management
Entity (MME), load balancing, traffic monitoring, Quality of
Service (QoS), etc. NFV decouples network functions
functionality from infrastructure and relocates the network
functions from dedicated appliances to pools of resources
leveraging commodity-of-the-shelf (COTS) hardware. In
addition to this, it also includes softwarization of the network
enabling automation of deployment and operations [16]. The
Management and Orchestration (MANO) framework is
essential to handle the virtualized elements and slices. The
European Telecommunication Standards Institute Network
Functions Virtualization Industry Specification Group (ETSI
ISG NFV) has created an interoperable architecture framework
for the MANO of infrastructure resources, VNF and Network
Services as composition of VNFs, depicted in Fig. 2 The
purpose of the ETSI ISG NFV is to enhance the NFV
framework to make it more supportive for 5G. [17]
Fig. 2. ETSI ISG NFV architecture framework, adapted from [17]
C. Blockchain and Smart Contracts
BC is a decentralized transaction and data management
technology developed first for Bitcoin cryptocurrency [18]. In
practice, a BC is a distributed database solution maintaining a
continuously growing list of data records that are confirmed by
the nodes participating in it. The data is recorded in a public
ledger, including information of every transaction completed.
This kind of decentralized solution does not require any third-
party organization in the middle. The information about every
transaction completed is shared and available to all nodes. This
makes systems more transparent than centralized solutions. [5]
A BC network is Peer-2-Peer (P2P) network. For example,
the Bitcoin network is run by nodes which collectively validate
the information submitted by other nodes. The process is as
follows [18]:
1) New transactions are broadcast to all nodes.
2) Each node collects new transactions into a block.
3) Each node works on finding a difficult proof-of-work
for its block.
4) When a node finds a proof-of-work, it broadcasts the
block to all nodes.
5) Nodes accept the block only if all transactions in it are
valid and not already spent.
6) Nodes express their acceptance of the block by
working on creating the next block in the chain, using
the hash of the accepted block as the previous hash.
The main invention of pseudonymous creator “Nakamoto”
of Bitcoin was a decentralized consensus mechanism between
participants/nodes in P2P network [19][20], which allows
pseudonymous participants to agree on the contents of the
distributed database, Blockchain. Novel ways to use a number
of existing technologies were discovered, which together
formed a system with emergent properties, previously
considered impossible to implement [20].
The nodes in BC are anonymous, which makes it more
secure for other nodes to confirm the transactions [5].
Utilization of cryptography enables authoritativeness behind all
interactions [6]. For example, Bitcoin uses the public key
cryptography in a novel way: Address is essentially a public
key and anyone knowing the matching private key can unlock
any funds associated to it. The public key can be associated to a
bank account and the matching private key to its password.
Public key cryptography is a framework where a key pair is
generated and then used to control the access to information.
Public key, as the name states, can be publicly available to
anyone, whereas private key must be kept secret by the owner.
The owner of the private key can use the key to sign any
message after which anybody who knows the public key can
verify that the signature attached to the message is valid. It is
therefore possible to verify that the messages with digital
signature have been written by a person who knows the
matching private key. [21]
Digital signatures can be used to verify for example that the
person trying to spend the money controls the private key.
Traditionally there has been a central authority to control that
the money can only be spent once, but “Satoshi Nakamoto” on
his paper [18] describes a decentralized framework to handle
the double spend problem. The solution is a distributed time
stamp server where a number of transactions are collected into
blocks that are then chained together in a temporal order. For a
block to be valid, all transactions in it must not be double-
spends. Fig. 3 presents an example about chained blocks in
timeline. [22]
Fig. 3. Chained blocks in timeline, adapted from [22]
Potential deployment considerations found in research and
early trials, particularly in the financial sector, include
throughput, scalability and latency in large public BCs, legal
enforceability, transactional confidentiality particularly in the
public BCs, consensus mechanism determination &
complexity, and integration with legacy systems and
workflows [6].
Smart contracts are self-executing scripts that reside on the
BC. Smart contracts enable automation of complex multi-step
processes. Integrating smart contracts to BC enable proper,
distributed, heavily automated workflows [6]. Szabo [23]
introduced smart contract concept in 1994, and defined it as “a
computerized transaction protocol that executes the terms of a
contract'”. In BC context, smart contracts are scripts stored on
the BC enabling general purpose computations occur on the
chain. Smart contracts operate as autonomous actors and the
behavior of those is fully predictable. Since the smart contracts
reside on the chain and have a unique address, the code can be
inspected by every network participant, and all the network
participants get a cryptographically verifiable trace of the
contract's operations. A smart contract can be triggered by
addressing a transaction to it. After this it executes
automatically every node in the network, according to the data
provided when triggering the transaction. [6]
Several companies and public organizations/foundations
develop BC platforms that are mostly open sourced. The
platforms enable fast prototyping, development and
deployment of new BC applications. The platforms can be
categorized to Bitcoin based, FinTech, Consortium/ Enterprise,
Sidechain/Anchored, and Smart contract platforms. Smart
contract platforms enable building and enforcing smart
contracts on top of the BC. In these platforms, complex logic
beyond simple cryptocurrency transfers are expressed utilizing
a programming language. Smart contracts have lots of
applications in different domains. Smart contracts can enable
decentralized applications, like voting, auctions, lottery, escrow
systems, crowd funding and micropayments etc. [24]
III. B
LOCKCHAIN
S
LICE
L
EASING
L
EDGER
C
ONCEPT
As described in Chapter II, network slicing enables multi-
tenant on-demand network infrastructure provisioning assuring
isolation/security. In addition to this, it can scale the resource
needed to fulfill the required SLA. The 5G network slice-
brokering concept relies on the ability of the mobile network
operator/service provider to easily and automatically negotiate
with external tenants network slice requests based on the
current resource availability from the infrastructure provider.
The challenge is how the needed slice could be leased
automatically in use by manufacturing equipment [25].
Samdanis et al. [3] have addressed the issue by proposing the
concept of 5G network slice broker that could lease network
resources on-demand basis. Next, we shortly review the
concept, and introduce our contribution in which we study how
BC could be used to deploy and enhance the operation of the
network slice broker and 5G network management layer.
A. Background
The basic concept of brokering network capacity on-
demand was presented by Samdanis et al. already in 2014 [7].
The idea was to enable automatic sharing of designated
network capacity so that, e.g., hosting RAN (Radio Access
Network) provider could offer its excess network capacity to
other operators or Mobile Virtual Network Operators (MVNO)
on-demand basis. Since then, Samnadis et al. have expanded
their concept to more general 5G Network Slice Broker that
operates as a mediator, mapping multiple tenants’ varying SLA
requirements to physical network resources. The Slice Broker
has three main tasks:
1) on-demand resource allocation
2) admission control based on traffic monitoring and
forecasting
3) RAN scheduler configuration which is influences the
way tenants can allocate the resources
5G Network Slice Broker is designed to be 3GPP compliant
and builds on the 3GPP Service and System Aspects Telecom
Management (3GPP SA5) network sharing management
architecture [3]. As shown in Fig. 4, the Broker is in Master
Operator-Network Manager (MO-NM) where the information
needed for its operation is available through Type 5 interface to
Sharing Operator Network Manager (SO-NM) and through
Type 2 interface to shared RAN. It is important to note that
there is no direct relationship between infrastructure providers
(InPs) and tenants like MVNOs, vertical markets and OTTs but
Mobile Service Provider (MSP) only intersects between these
stakeholders. MSP can also acquire the necessary network
resources from one or more InPs. [25] The Slice Broker can
serve two kinds of service requests. First, it can get SLA based
resource allocation requests from MVNOs through SO-NM,
and after the admission control, it configures the network slice
to best suit the service requirements. Secondly and even more
revolutionarily, the Broker can also provide services to vertical
industries (industrial, automotive, e-health,) and OTT providers
(video, voice,..) with the help of Service Capability Exposure
Function (SCEF) module [26] which enables authorized and
secure access to 3GPP system service capabilities through
Application Programming Interfaces (API). SCEF assists in
many tasks like authentication / authorization, charging,
Quality of Service (QoS) provision and SLA monitoring as
well as supplying user context information. Therefore, SCEF
can be regarded as one of the key enablers for network
programmability, which thus benefits also third parties.
Fig. 4. 5G Network Slice Broker Concept management architecture adapted
from [3]
To support on-demand resource allocation, some
enhancements and extra signalling are needed for existing
interfaces. For instance, it will be important to distinguish
tenants so that their corresponding data traffic and SLA
performance indicators can be tracked. To tackle this,
Samdanis et al. [3] propose the introduction of tenant identifier
parameter to be included in every data packet and performance
report. Equivalently a service identifier parameter would help
differentiate vertical players and OTT providers. In addition to
these, a set of extra parameters are also needed for supporting
particular SLA and timing requirements, which thus can
change dynamically, e.g., the information about the amount of
resources allocated, service timestamps and QoS data must be
intermediated through interfaces.
B. Slice Leasing Ledger
In this section, we will consider how BC based approach
could facilitate the efficient operation of 5G Network Slice
Broker.
By combining advanced cryptography, consensus
mechanisms and distributed network structure, the BC provides
some features that have not been viable using existing digital
structures. The main advantage achieved by applying BC is
getting a trust layer to one’s system that lowers the barrier to
collaborate and enables building a larger efficiently ecosystem.
Next, we present how the Network Slice Broker concept can
benefit from BC working as a ledger in it. We call this
enhanced concept a Slice Leasing Ledger. In a BC based
system, every stakeholder has own unique digital keys which
can be used to sign and verify transactions. Further, in a
permissioned BC system like the Slice Leasing Ledger, these
keys are tightly interconnected to stakeholders’ identities.
Thus, in the Slice Leasing Ledger, every single tenant, actor
and stakeholder who takes part in slice leasing activities, has its
own keys with verified identities. This creates the foundation
for verifiable transactions which can be used for charging and
billing as well as SLA agreements.
Furthermore, BC based smart contracts will be outstanding
advance in automation of simple and repetitious negotiations as
well as in enforcement of straightforward agreements related to
many slice brokering operations. Negotiations on SLAs
become more efficient as QoS levels and prices work as smart
contract parameters. Similarly, network resource allocation
with help of MO-NM can be handled by smart contracts. When
both negotiators agree on service terms, the contract agreement
is timestamped with verified signatures and saved in the BC.
Since everything happens digitally, devices can manage
negotiations themselves based on pre-defined rules and
policies. Because of determinism requirements, smart contracts
are not able to fetch external data on their own but they need an
oracle for creating reliable connection to a data source [27]. In
the case of Slice Ledger, e.g., information about realized SLA
service level needs to be intermediated through the oracle so
that the data can be used for charging or possibly compensating
SLA violations.
The distributed nature of a BC makes the data storing in BC
itself relatively expensive. Therefore, only necessary
information is saved in BC, and as far as the Slice Ledger is
concerned, this data could be, e.g., timestamps when service
has started/terminated, agreed QoS parameters, selected
performance data and charging evidence. Modern BC platform
initiatives like Hyperledger [28] provide membership services
like registration and identity management as a part of their
platform. This could ease the authentication and authorization
tasks of SCEF. Further, this system could be developed
towards reputation based [29] broker platform in which all
actors would have objective “reputation points” depending on
their measured performance and how well do they qualify for
agreements. This reputation feature may become even more
valuable in micro-operator environment with various not-so-
well-known service providers [26].
The greatest benefits that would be achieved by applying
BC in Slice Ledger would be savings in the coordination and
transaction costs. Because BC provides the platform for
negotiations that most importantly are trustworthy enough to
enable automatic agreements, slice negotiation process speeds
up as well as the cost of a single slicing agreement collapses.
Secondly, security enhancement is another advantage of BC.
While network resources can indeed be considered as a critical
infrastructure, the distribution of control functions provides no
single point-of-failure or target for, e.g., Denial-of-Service
(DoS) attacks.
In a permissioned consortium BC concepts, privacy issues
are very well addressed as stakeholders are known, albeit often
at the expense of compromised security [30]. Moreover, the
cosiderations related to size and consensus model of the
blockchain (affects latency, scalability, throughput, energy
consumption and storage usage) are not so prominent in
permissioned BCs. Another thing to note is that also the use of
smart contracts is still strongly evolving. To date, they are not
legally recognized and there will always be use cases that
cannot be resolved inside digital contracts only [27]. It will be
important to identify these ultimate situations and plan how
these can be resolved, probably outside the BC,e.g., through a
hybrid paper-plus-code model where contracts are verified for
authenticity via BC, but paper backups are also be filed for the
purposes of traditional recourse.
In our current scenario, the BC based Slice Ledger would
be operated by one network operator as a consortium BC with
known participants. Naturally, new tenants and MVNOs could
be added to a participant list as needed. Since RAN
configuration is separated from Slice Ledger with MO-NM, the
lower level RAN element managers or Master Operator-shared
RAN domain manager are not directly the participants of the
Slice Ledger but merely are visible as network resource
parameters available for the smart contracts of the Slice
Ledger. Anyhow, we see that to take full advantage of the
potential of BC and 5G local micro-operators [26], in the future
the Ledger could be totally shared between participating
operators and correspondingly the Ledger would work more
and more as a Network Resource Marketplace beyond the
transaction facilitator.
IV. A
NALYSIS OF THE
B
LOCKCHAIN
S
LICE
L
EASING
L
EDGER
C
ONCEPT
A
PPLICABILITY TO THE
F
O
F
In the section, Factory of the Future use case is defined
based on the requirements discussed in Section II A, and BC’s
applicability to the Slice Ledger accessed.
A. Factory of the Future Use Case Description
Selected Factory of the Future digital automation 5G
Network Slice Leasing BC use case utilizes 5G Network Slice
Broker in a BC to enable manufacturing equipment
autonomously and dynamically to acquire the slice needed for
more efficient operations and reduced service creation time.
Manufacturing equipment lease independently network slice
required for efficient operations on-demand, approve SLA and
pay for the service according to actual usage. Network slice
trading will be performed in BC. BC smart contract order slice
orchestration according to agreed SLA from 5G Network Slice
Broker. The SLA between a manufacturing equipment and a
network operator will invariably include QoS parameters,
where QoS Class Identifiers (QCIs) characterize service in
terms of priority, packet delay and packet loss. Furthermore,
Key Performance Indicators (KPIs) will be defined for
monitoring the performance per QCI. Time stamping of the
utilized network slice and dynamic billing according to actual
usage is handled by BC. Whole process is automated and
requires no human intervention.
1) Workflow Enabled by Slice Leasing Ledger Blockchain
Fig. 5 presents concept of manufacturing equipment’s
autonomous slice leasing in 5G NFV and SDN infrastructure
by utilizing 5G Network Slice Broker and Slice Leasing
Ledger BC with smart contracts. 5G infrastructure consist of
physical infra, NFV infra, NFV management and organization
(NFV-MANO), and Operations Support System/Business
Support System (OSS/BSS). Brokering will be managed by 5G
Network Slice Broker [3] and actual leasing, billing and payout
by the introduced Slice Leasing Ledger in the service layer.
Fig. 5. Concept of slice leasing by manufacturing equipment in 5G NFV
infrastructure.
The workflow of the use case is following. Manufacturing
equipment requests specific slice for lease from Slice Leasing
Ledger and accepts corresponding SLA. Slice Leasing Ledger
orders the slice orchestration according to agreed SLA from 5G
Network Slice Broker. Manufacturing equipment operates in
leased slice and 5G Network Slice Broker provides information
about actual usage to Slice Leasing Ledger. Slice Leasing
Ledger performs transactions between actors’ wallets.
2) Actors, Stakeholders and Interests
Infrastructure providers (InP) owns and manages all or
parts of the network infrastructure assets. InP benefits from a
need for infrastructure, and get income from leased
infrastructure resources (IaaS), and can reduce OPEX.
Mobile network operators (MNOs) or third parties that
acquires and operates the network of InP resources, and
interact with other players but not directly with end users.
MNO role can merge with with InP role, and act as a Service
Provider (SP) towards tenants. They get income from utilized
network (NaaS/PaaS) according to SLAs, can automate
trading, brokering and billing and this way reduce OPEX.
Tenants are business users using connectivity services
based on a pre-defined SLA, through leasing resources from
MNO/SPs to expand their service businesses. It can be a
Mobile Virtual Network Operator (MVNO), an enterprise, an
Over-The-Top service provider (OTT) or a vertical service
company. They can automate trading, brokering and billing as
well as reduce CAPEX and OPEX.
Manufacturing equipment owners/users consumes services
from tenants benefiting from autonomous manufacturing,
efficient operations, automated on-demand service, easy
agreements and payments, cost according to usage and reduced
OPEX and CAPEX.
SW and HW vendors can sell equipment / technology in
different areas, spaces and buildings, and can deliver better-
tailored customer service. This will happen more and more
utilizing on-demand cloud platforms and aaS business models.
Several new value proposition and/or supporting process
based multi-service, multi-tenant business models, and
stakeholder roles and relationships are enabled in this kind of
environment including, e.g., provision of network assets,
connectivity or managed services, data collection or its pre-
processing as-a-service for factory tenants [25]. Furthermore,
brokering and leasing can be extended to other 5G network
assets, e.g., virtualized computing, storage, Core Network and
microservices on the edge and central clouds.
B. Blockchain’s Applicability to the Slice Ledger
The technical applicability of BC for the use case is next
summarized using the BC characteristics discussed in Section
II C and analysis framework by Greenspan [30]:
1) Shared database write access with multiple writers,
2) Absence of trust between multiple writers,
3) Disintermediation,
4) Interaction and dependence between transactions
5) Nature of assets and connection to real life, and
6) Control of functionality, consensus & validators, related to
applicability of the public, hybrid or private BC options.
TABLE I. S
UMMARY OF BLOCKCHAIN APPLICABILITY ANALYSIS
Shared
write
Absence
of trust
Disinter-
mediation
Interaction Connection Control
Yes Yes Yes Yes Yes Hybrid/
private
To summarize, BC technology shows high potential to
fulfill the needs of slice brokerage leveraging in its key
characteristics. As for the cross domain uses in general, the
nature of assets and their connection to real life is an area for
further research, e.g. related to use of oracles, microtransaction
sidechains.
V. C
ONCLUSION
In multi-actor trading and leasing systems, absence of trust,
requirements for automation, needs for fast and cost efficient
transactions, and unwillingness to manage centralized systems
drive solutions towards decentralized transaction and data
management. This apply also when trading, managing and
orchestrating network resources in next generation 5G
networks. This paper presented the novel Blockchain Slice
Leasing Ledger Concept and analysis of its applicability in the
Factory of the Future. The concept utilizes 5G Network Slice
Broker in a blockchain to enable manufacturing equipment
autonomously and dynamically acquire the slice needed for
most efficient operations. Multi-operator slice creation requires
the establishment of mutual trust relationships between the
operators. Fast and cost efficient leasing transactions are
required. For this kind of dilemma blockchain technology was
found to offer an efficient solution.
In the researched Factory of the Future use case,
manufacturing equipment lease independently network slice
required for efficient operations on-demand. Network slice
trading is performed in blockchain, and its smart contracts
order slice orchestration from slice broker. Whole process is
automated and requires no human intervention. Introduced
novel concept and application of blockchain technology to the
management of virtual 5G network slices lowers the barrier for
network, and enables several new end-to-end business models
including provision of connectivity or managed services for
factories as well as IT infrastructure, data collection or its pre-
processing as-a-service. Future work could consider analysis of
other context aware, multi-service, multi tenant use cases.
Future research is needed relating to blockchain technology
integration surrounding “real life” systems, and in the areas of
collaborative business models and regulation. Next phase of
this research is to evaluate the Slice Leasing Ledger from
business, policy and legal perspectives before the system
requirements and architecture.
A
CKNOWLEDGMENT
The work is done in Blockchains Boosting Finnish Industry
(BOND) project partly funded by Tekes the Finnish Funding
Agency for Innovation.
R
EFERENCES
[1] NGMN Alliance, “NGMN 5G White Paper,” 2015.
[2] NGMN Alliance, “Description of Network Slicing Concept,” Version
1.0, January 2016.
[3] K. Samdanis, X. Costa-Perez, and V. Sciancalepore, “From Network
Sharing to Multi-Tenancy: The 5G Network Slice Broker,” IEEE
Communications Magazine — Communications Standards Supplement,
July 2016.
[4] A. Jøsang, C. Keser, and T. Dimitrakos, “Can we manage trust?,” in
International Conference on Trust Management, Springer, pp. 93–107,
2005.
[5] J. Yli-Huumo, D. Ko, S. Choi, S. Parka, and K. Smolander, ”Where Is
Current Research on Blockchain Technology?—A Systematic Review,”
2016.
[6] K. Christidis, M. Devetsiokiotis, “Blockchains and Smart Contracts for
the Internet of Things,” Special Section in IEEE Access: The Plethora of
Research in Internet of Things (IoT), Vol 4, 2016, pp. 2292-2303.
[7] 3GPP, “Study on management and orchestration of network slicing for
next generation network,” 3GPP TR 28.801 v1.2.0, May 0.4.0, 1 2017.
[8] Nokia, ”Dynamic end-to-end network slicing for 5G - Addressing 5G
requirements for diverse services, use cases, and business models,”
White Paper, 2016.
[9] 5G PPP, “5G and the Factories of the Future,” White Paper, 2014, URL:
https://5g-ppp.eu/wp-content/uploads/2014/02/5G-PPP-White-Paper-on-
Factories-of-the-Future-Vertical-Sector.pdf
[10] IEC, “Functional Safety and IEC 61508,” International Electrotechnical
Commission (IEC), URL: http://www.iec.ch/functionalsafety/
[11] S. A. Ashraf, I. Aktas, E. Eriksson, K. W. Helmersson, and J. Ansari,
“Ultra-Reliable and Low-Latency Communication for Wireless Factory
Automation: From LTE to 5G”, Proceedings of IEEE conference on
Emerging Technologies and Factory Automation, Berlin, Germany,
September 2016.
[12] B. Holfeld, D. Wieruch, T. Wirth, L. Thiele, S.A. Ashraf, J. Huschke, I.
Aktas, and Junaid Ansari, “Wireless Communication for Factory
Automation: An Opportunity for LTE and 5G Systems”, IEEE
Communication Magazine, June 2016.
[13] A. Müller, “Chancen & Herausforderungen von Industrial Radio aus
Sicht der Industrie,” Bosch GmbH, VDE Kongress, October 2016.
[14] ZDKI, “Industrial Radio,” URL: industrialradio.de/Menu/Home/ZDKI
[15] C.J. Bernardos, A. De La Oliva, P. Serrano, A. Banchs, L.M. Contreras,
H. JIN, and J.C. Zúñiga, “An Architecture for Software Defined
Wireless Networking,” IEEE Wireless Communications, Research and
Standards: Leading the Evolution of Telecom Net work Architectures,
June 2014.
[16] Software Networks Working Group, “Vision on Software Networks and
5G”, White Paper, 2017.
[17] J. Triay, “NFV as a 5G Infrastucture Enabler,” Presentation at ETSI
Summit on 5G Network Infrastructure , 6 April 2017.
[18] S. Nakamoto, “Bitcoin: A peer-to-peer electronic cash system,” 2008.
[19] M. Gault, “Increasing Healthcare Security with Blockchain
Technology”, 2016, URL: https://guardtime.com/blog/
increasing-healthcare-security-with-blockchain-technology
[20] M.J. Fischer, N.A. Lynch, and M.S. Paterson, “Impossibility of
distributed consensus with one faulty process,” Journal of the ACM
(JACM), 32(2), 1985, pp.374-382.
[21] S. Driscoll, “How Bitcoin Works Under the Hood, ” 2013, URL:
http://www.imponderablethings.com/2013/07/how-bitcoin-works-under-
hood.html
[22] BitGo, “The Challenges of Block Chain Indexing,” 2015, URL:
https://blog-archive.bitgo.com/the-challenges-of-block-chain-indexing/
[23] N. Szabo, “Smart Contracts,” 1994, URL:
http://szabo.best.vwh.net/smart.contracts.html
[24] A. Baliga, “The Blockchain Landscape,” Persistent Systems, 2016.
[25] H2020-ICT-2014-2 5G NORMA, “Deliverable D2.1: Use cases,
scenarios and requirements,” V1.0, 2015.
[26] M. Matinmikko, M. Latva-aho, P. Ahokangas, S. Yrjölä, and Timo
Koivumäki, “Micro operators to boost local service delivery in 5G,”
Wireless Personal Communications journal, Springer, May 2017
[27] K. Lauslahti, J. Mattila, and T. Seppälä, “Smart Contracts - How will
Blockchain Technology Affect Contractual Practices?,” ETLA Report
No. 57, 2016.
[28] Hyperledger Project, Linux foundation, 2016, URL:
https://www.hyperledger.org/
[29] D. Tapscott, and A. Tapscott, “Blockchain Revolution: How the
Technology Behind Bitcoin Is Changing Money, Business and the
World,” Portfolio Penguin, 2016.
[30] G. Greenspan, “Four genuine blockchain use cases,” 2016, URL:
https://www.linkedin.com/pulse/four-genuine-blockchain-use-
casesgideon-greenspan
