Conference PaperPDF Available

Autonomous Edge Resource Organization with Smallcell Integration in 5G

Authors:
Autonomous Edge Resource Organization with
Smallcell Integration in 5G
Ahsan Malik, Xun Xiao, Ramin Khalili,
Zoran Despotovic and Artur Hecker
German Research Center, Huawei Technologies
M¨
unchen, Germany
{ahsan.n.malik, xun.xiao, ramin.khalili,
zoran.despotovic, artur.hecker}@huawei.com
Mayutan Arumaithurai and Xiaoming Fu
Institute of Computer Science
Georg-August-University of G¨
ottingen
G¨
ottingen, Germany
{mayutan.arumaithurai, fu}@cs.uni-goettingen.de
Abstract—In the upcoming 5G era, many new use cases (e.g.
emergency situations, crowded sports event coverage, etc.) are
expected to be supported. Additionally, to improve latency and
jitter, 5G is likely to support edge computing capabilities, e.g.
in an NFV and MEC fashion. These features and requirements
call for support for autonomous networking, where links, nodes
and their services cannot be presumed permanent, but rather
have to be dynamically used, when available and suitable. In this
paper, we propose a new design framework, named Aerosmith,
which provides autonomous edge resource organization with
smallcell integration and topology handling. We motivate our
design, explain the key architectural decisions and our prototype
implementation, and provide initial evaluation results.
Index Terms—Autonomous, Small Cells, MEC, 5G Networks
I. INTRODUCTION
In the previous generations of mobile networks, the con-
nectivity provision to the base stations (BSs) mostly relied
on available copper and optical means or used microwave or
satellite backhauls. In 5G [1], the upcoming next generation,
new use cases have been identified (such as support for
emergency situations, crowded sports event coverage, etc.)
in 3GPP SA1 [2]. Those new use cases require a rapid,
sometimes even on-demand, rollout or extension of a cellular
network into a new area, often with guarantees, e.g. enough
capacity, high reliability or low latency.
Radically novel in these emerging use cases is the unfore-
seeable usage patterns at the moment of network deployment:
in 5G, both the network topology (BS placement, their inter-
connection, etc) and the network services will change during
network lifetime. Thus, additionally to long-term network
planning, rapid operational decisions will have to be used:
as backhauls and network topologies cannot be planned cost-
efficiently in this situation, the future mobile networks must
be more adaptive and malleable. For instance, small mobile
cells could be placed to reach BSs with good backhaul
connectivity. Similarly, an available macro-cell fronthaul can
be used as aggregate backhaul. In the newest products, basic
provisions for both BS-to-BS connectivity (e.g. X2 interface)
and fronthaul-backbaul integration (e.g. Huawei’s X-HAUL1)
are available via pre-configuration.
1http://www.telecomtv.com/articles/5g/huawei-launches-x-haul-mobile-
bearer-solution-for-5g-networks-15883/
The pre-provisioning approach is problematic due to the
fact that the connection of a BS (both to the mobile core
network services and to the public data networks) might be
provisioned over an unstable path, subjected itself to control
and management decisions of the (same) operator. Specifically,
redirecting flows triggered by traffic engineering due to load
fluctuations can easily lead to control path instability or its
loss. Consider e.g. a scenario, where an operator downgrades
or blocks forwarding on a port of one BS, currently relaying
control plane communications of some other BS; today, that
would lead to a full disconnect of the relayed BS from the
mobile core network. Coping with such situations from a cen-
tral point of view of an operator requires exact understanding
of the current, albeit dynamic, network topology and a precise
schedule of operations, where commands must follow specific
order to avoid lockouts. This is difficult to implement in a
scalable way.
In addition, to improve latency and jitter, 5G is likely to
support edge computing capabilities, e.g. in NFV [3] and
MEC [4] fashion. This requires dynamic deployments of
network functions (NFs) in 5G BSs, which allows to deploy
core network services directly on the edge. Hence, 5G BSs
should be also able to discover, select and connect to the most
suitable NF instances. In fact, 3GPP SA2 has recently defined
a service-based architecture (SBA) with a service-based inter-
face (SBI) between NFs to support similar provisions in the
core [5], [6]. Clearly, a mechanism is needed to allow MEC-
enabled 5G network nodes (e.g. BSs) to dynamically handle
their participation in the SBI as well.
Beyond the well-known radio coordination problems, the
resulting trend to denser but more dynamic small cells in 5G
raises new questions with regard to the integration, connec-
tivity and coordination of the numerous BSs and the whole
system architecture. Overall, these features and requirements
call for support for autonomous networking, where links,
nodes and their services cannot be presumed permanent, but
have to be dynamically used, when available and suitable. This
is radically novel in the mobile network area, rather char-
acterized by strong operator involvement, network planning
activities and reliance on session-oriented protocols used over
guaranteed and operator-provisioned connectivity. To the best
of our knowledge, we are not aware of any previous work
that solves both a dynamic interconnection of many small
cells in the mobile network RAN and allows their autonomous
establishment and maintenance of an SBI.
In this paper we present Autonomous Edge Resource Or-
ganization with SMallcell Integration and Topology Handling
(Aerosmith) solution. More concretely, this paper makes the
following contributions:
We design a novel, dedicated and simple, architecture to
support fully autonomous resource integration, connec-
tivity and backhaul maintenance to support rapid (e.g.
mobile BS) deployment.
We propose necessary mechanisms to enable an au-
tonomous, i.e. even core-less, BS operation in the future
generations of mobile networks, where BSs participate in
an existing or span a new SBA support layer.
We implement our proposals using real networking stacks
and evaluate the proposed mechanism. Our results show
the feasibility of our solution and provide insights about
its design.
Our proposal is complementary to SA2 work in 3GPP, provid-
ing a solution for SBI. With Aerosmith, the 5G system could
be living on the edge of the small cells.
The rest of the paper is organized as follows. In Section II,
we describe our formalization of the problem, i.e. our mod-
eling based on the above observations. In the Section III, we
present technical details of our solution. After that, simulation
results are presented in Section IV. Finally, we survey some
related work and conclude the paper.
II. SY ST EM MO DE L
In our system model, we assume a mobile RAN covering
a geographical area. Formally, we denote the mobile RAN
infrastructure as G:= hS, Eiwhere Sis the set of BSs, in
which every sican have networking, compute and storage
capabilities (but with different and varying resource because
of allocations). Eis the link set, in which every link eij is
a bidirectional communication link between two BS nodes
siand sj. Over the network infrastructure G, BSs need a
control plane interconnectivity so that NFs running across the
infrastructure can communicate with each other to provide
network services.
Since the network topology is dynamic, both the BS set
and the link set Eare not static and could change due to
the network churn (e.g. any possible node/link failures, node
joining/leaving, and/or port blocking by NFs). As a result,
the control plane connectivity could also be affected and
network services could be broken. Our solution provides a self-
organized control plane establishing such interconnectivity and
supporting service discovery. The control plane constructed
spans all available resources within a control realm. We will
introduce details of our solution in the next section.
Note in the previous paragraph an important detail related
to the terminology that we use in this paper: We use the
term resource control plane (or just control plane) to denote
a set of resources (or agents that manage them, see next
section), along with a set of protocols to establish and maintain
interconnectivity among them, as well as provide basic storage
capabilities. The later term, control plane namely, will be more
frequently used, i.e. whenever there is no danger of confusing
it with the control plane of a mobile network.
III. OUR PRO PO SA L
Our solution features a zero-configuration, self-
bootstrapping and self-maintaining communication service
supporting different types of resource control plane
communications. It supports both resolution of end-points,
node to node path setup and maintenance and piggy-backing
messages of other protocols on top of the control plane (e.g.
OpenFlow or network management protocols like NETCONF
etc). The rationale behind our design is that 5G, and future
networks in general, should exhibit more autonomies, i.e.
giving away management and adopting more control. For
example, failures in the network should not be handled
through an ensemble of the tasks such as network planning
for resilience and network management, but rather resolved
by the network itself through its self-healing properties. That
should also, in our opinion, resonate better with the SB
architecture of 3GPP [5], [6].
A. Infrastructure Requirements
There are two requirements on the infrastructure for the
proposed solution to work:
1) Every node in the infrastructure must execute a resource
control agent (RCA).
2) Every RCA on an infrastructure node must have a local
connectivity to at least one other RCA.
An infrastructure (resource) node can be any node in the
network, e.g. a BS, a server hosting a specific network function
or a data center that hosts a multitude of them.2The RCA is
a piece of dedicated software designed for and running on the
BS as implemented by the vendor or integrator of the resource.
As a rough example, RCA can be compared to standard agents
(e.g. OpenFlow or SNMP) in the network appliances.
The execution of the RCA is just the representation of
the controllability of the resource and can be compared to
the presence of OpenFlow clients in OpenFlow switches. As
for the connectivity requirement, it means that we do not
consider lower layer channel/transport issues here; the channel
can be a physical medium (layer 2 link) or a virtual channel,
spanning uncontrollable resources (public paths, VPN, etc).
This also answers the question whether everything needs to
be controlled. If the condition 2 is not fulfilled, then the
mobile RAN essentially falls apart in two (smaller) networks.
Interestingly, each part will remain controllable, as long as
there is a control end point within it.
RCA needs some initial configurations. The self-
bootstrapping allows to minimize that configuration to
the bare minimum: every RCA only needs to have an
2We will often use the term BS to mean an infrastructure node. There is
nothing radio access specific in our usage of the term base station.
identifier and a security association (SA). An identifier can
be derived from the resource (e.g. the MAC address of the
management port, etc) and depends on the available SA: in
practice, we expect it to be attached to a private/public key
pair. The SA must have a control realm name. This name
can be explicitly given as a string, or it could result from
the signatory information in the certificate (e.g. X.509) that
might be used to confirm the public key to id binding.
In our solution, the RCA acts both as a local resource
control element and as a control plane peer. The local resource
control part mainly provides access to the controllable objects
of the resource. RCA internally links the local control and
the RCA peer. For instance, it uses local log files, errors and
alarms to reconfigure the constructed control plane in case of
problems, enabling local and, thus, fastest detection. For the
latter as an RCA peer, the RCA implements the resource-
to-resource (R2R) protocol suite, enabling it to exchange
messages with other RCAs.
B. RCA Peer Operations
Interactions between RCA peers are the main activity con-
stituting the control plane. In an RCA, a Message Processor
is responsible for the internal treatment of the R2R protocol
and the delivery of the contained messages. R2R protocol runs
when the RCA starts up, it periodically runs Friend Discovery
(FD), neighbor selection (NS) and Routing modules. The
output of FD module is made available to the NS module.
The output of NS module is made available to Routing
module. Additionally to periodic execution, the RCA runs
these modules in case of alarms. We here further detail the
activities in different phases.
1) Friend Discovery: When a node of a mobile RAN (i.e.
a BS) initially comes up, its RCA needs to find other RCAs
from the same control realm. This is usually referred to as
bootstrapping. The only input to this process is the initial
configuration and, if available, the friend list from previous
operations. RCA should use a mix of different approaches to
find friends (UPnP, mDNS, SDP, DNS-SRV, special nodes,
etc) depending on infrastructure capabilities and the nature of
the network element. The overall active friend list is regularly
updated and made available to the NS module.
2) Neighbor Selection: Given a list of active friends, the
decision becomes necessary, which of them an RCA will
connect to, i.e. which of these it will consider as control plane
routing next hops. Assuming that freedom of choice exists
in the infrastructure, that decision is paramount because the
choice of the nodes defines the overlay structure of the control
plane. That structure has a major impact on the resulting per-
node state and possible communications in the control plane as
well as the resilience of the whole. We engineered the control
plane to fulfill QoS and resilience requirements in a pragmatic
manner, in particular without overloading resources.
Different strategies for neighbor selection typically lead
to various types of overlay structures from graph-theoretical
perspectives. If most of the nodes select several specific nodes
in the network as friends, then such a selection policy will lead
to a centralized topology. Oppositely, if everyone randomly
selects its friends, the resulting topology will be more random.
In between, the topology will present scale-free properties.
Alas, one realizes that a perfect structure does not exist.
Higher degree structures exhibit a better resilience and good
QoS posture but induce a high maintenance cost and scale
badly. Scale-free networks have very good scaling properties
but rely on high degree nodes that are easy targets for an
intelligent attacker. Balanced solutions such as uniform degree
networks or generic small worlds represent trade-offs: while
their resilience is worse than that of random networks or full
meshes, their QoS guarantees are lower than what can be
achieved with full meshes or scale-free networks.
Since no structure exhibits all desired properties, the neigh-
bor selection phase makes the topology of the constructed
control plane be structurally adaptive. We refer to this process
as rewiring: following a trigger, the RCA is able to find
other neighbors in order to adopt the appropriate system-level
shape, following the service degradation doctrine. Instead of
guaranteeing all properties at all times, this idea advocates
guaranteeing some properties depending on the context. For
instance, in normal operational conditions, good QoS and low
node foot-print would appear as primary objectives. However,
in case of repetitive faults and errors, the system can go
into a degraded or protected mode, where resilience prevails
on quality, and this up to a point where the communication
becomes restricted to only essential commands.
In dire straits, what matters is that the operator/decision
layer can still reach the RCA, so as to be able to get status
reports and/or to apply a different configuration.
3) Routing: Once all RCAs select their friends, the RCAs
can run separate, classic distributed routing protocols on the
available neighbors so as to decide how to reach each des-
tination (e.g. distance vector or link state protocols resulting
in the next hop neighbor for any destination). At least two
alternatives to this are available:
One could bind the routing to an infrastructural metric
instead and only use neighbors, which are closer to the
RE of the RCA in the transport infrastructure.
One could bind the routing directly to the neighbor
selection by passing the message from one RCA to
another according to a common metric, e.g. distance from
the intended recipient to ids of known neighbors. This
would allow to construct a distributed resolution service.
We choose the latter way. We use the network Linearization
algorithm proposed in [7], an id-based structured routing
protocol, for the routing module. Linearization is a simpler
form of what has been proposed in [8]. [8] also presents a
nice discussion on why id-based routing is at all a good choice
for routing. We point the interested reader to that discussion,
instead of repeating it here.
Along with routing, it is straightforward to organize a
distributed storage across the BS nodes, since the stored
objects and the RCA ids can be easily projected to the same
space using a hash function, similar to distributed hash tables
(DHTs) [9]. This is even easier in our implementation thanks
to the choice of the id-based structured routing. With this,
it is straightforward to store objects at a BS node closest to
the object. For higher availability, redundant storage can also
be easily organized, e.g. using several hash functions. This
storage is currently used as strictly internal to control plane
to allow to store global status and configuration information,
but can be easily extended to serve as an efficient implemen-
tation of the Universal Storage (USM) and Unstructured Data
Storage (UDSF) of 3GPP TS 23.501 [5].
C. Remarks
Aerosmith (especially, the constructed CP) is designed
as a multi-dimensional and dynamic interconnection of BS
resources within the same control realm. We delegate the
construction and maintenance of a CP to the RCA running
at every BS. This is a paramount design principle: first, doing
so has the advantage of being capable to react to local events
in the fastest manner; moreover, with smart algorithms, this
provides a good level of isolation from the decision layer:
even if decisions are disastrous with respect to the immediate
situation of a resource, they can be locally corrected so that
at least the logical binding to the CP and, hence, the decision
layer is always maintained.
As a simple example, if an SDN controller (i.e. a control
purpose NF running on a resource node) sends a flow rule to
a controlled switch s1to block forwarding on a port currently
used for control plane communications of some other switch
s2, in todays SDN that would lead to a full disconnect of s2
from the controller. This is particularly critical in OpenFlow-
based networks with an in-band control plane (or called control
channel). However, in our solution, the local RCA on s2will
reconnect to a different suitable RCA (e.g. to the one on s1).
Once reconnected in such an indirect way (RCA on s1acts
as a proxy for the RCA on s2), s2will notify the responsible
controller of the situation. The controller now can raise an
alarm or stop the responsible control application or restore
the previous state.
In the examples above, one could argue that the problem
can be centrally considered and solved at a network control
application. However, requiring correctness there would result
in a considerable complexity and unnecessary customization
of network control applications, increasing the development
effort and impeding their portability. The reasons are as
follows. First, the control graph details are irrelevant to a
casual developer and, ideally, should not play any role, so that
network applications can be reused in other control realms
or in changed infrastructure conditions. Second, this requires
instantaneous knowledge of the overall infrastructure situation,
which is a very hard requirement for a distributed system at
hand. Therefore, requiring correct decisions from a decision
layer is an unrealistic assumption and a bad design choice. It
would strongly limit the admissible infrastructure dynamics,
since non-local decision points cannot be informed in zero
time and might make wrong decisions. Further, it would
heavily shrink the scalability of the solution by imposing
tight synchronization requirements. Most importantly, it would
strongly increase the cyclomatic complexity of all network
applications, which contradicts the ease of programmability.
The proposed solution solves the issues on control plane
establishment and particularly its maintenance later on. With
a distributed system operating between RCAs and embedded
in the network infrastructure, it abstracts the controlled BSs,
integrates autonomously newly deployed BSs, keeps all BSs
connected, and makes the resources on the BSs always avail-
able to the developers of the network. The solution is one
of the key components enabling a fully programmable but
transparent network infrastructure for future mobile networks.
IV. EVALUATION
In this section, we show the evaluation results of different
aspects of RCA peer operations (cf. Section III). Every node
executes an RCA as per explanation above (cf. Section III-B).
To check the feasibility of Aerosmith, as well as assess the
costs associated with its creation and operation, we have a
running, proof of concept implementation of the system. Our
resource is a Linux host, running an OpenVSwitch (OVS) [10]
as the networking module and using the local file system for
storage purposes, implemented by 1000 lines python code.
The largest part is for routing module. The RCA design is
modular so that other protocols(e.g. RSTP or TRILL) can be
easily integrated as routing modules.
A. Evaluation Environment
Our RCAs run as OVS extension under Linux. Besides,
the same RCA is used on the node running the control
purpose NF (we use FloodLight controller3). In our evaluation
environment, each extended OVS represents a dynamically
deployable 5G small cell.
For topology deployment, we use a slightly altered version
of Mininet4, which permits us to run big topologies of such
initially unconfigured NOVS nodes and 1controlling nodes.
No routing and no other special provisions are implemented
(no routing protocol, no STP or other L2 auto-organization
solutions; the nodes even have no initial IP configuration,
no controller configuration, etc). The node degree in our
generated random topologies is 3on average.
On start-up, our local RCA installs initial basic flow rules in
the OVS so as to capture all R2R traffic; it also starts sending
out R2R packets over its local OVS using PACKET OUT.
Again: note that by the nature of RCA, there is no controller
yet at this stage. An RCA can only follow the procedure in
Section III-B to discover other RCAs in its neighborhood and
to actually construct and maintain the control plane.
We are interested to study the system bootstrapping time,
convergence time, and resuming time (these terms will be
explained in details in the following sections) on topologies of
different sizes (e.g. 50, 100, 150 and 200 nodes). We compare
the performance of two alternative schemes used by the routing
module in the proposed solution. The first is our choice (i.e.
3http://www.projectfloodlight.org/floodlight/
4http://mininet.org/
Linearization algorithm [7]) and the other one is the default
choice in the current OVS implementation (i.e. STP).
B. Control Path Bootstrapping Time
In this experiment, we are interested in the control path
bootstrapping time, i.e. time till RCAs are able to forward the
control plane messages to a selected endpoint (e.g. a controller
running on a specific network node), so that the TCP control
connection can be established from the OVS to those endpoints
in the network.
In the Figure 1, we can see that Linearization algorithm
bootstraps all control paths after 7seconds (resp. 8,10 and
13 seconds), for a network of size 50 nodes (resp. 100, 150,
and 200 nodes), while STP as shown in Figure 2 requires 33
seconds (resp. 33,33 and 32 seconds) to establish the control
plane connectivity. Hence, STP is a factor 4-7 times slower
than Linearization algorithm to bootstrap the network.
This experiment illustrates how long different choices for
the routing module take so that every nodes can connect to a
specific node in the network. It is quite relevant to the future
CP/DP-decoupled network architecture where every network
node does not have to connect to every other nodes but only
a controlling endpoint of the network.
C. Full Convergence Time
We now measure the convergence time, i.e. the time it takes
from the start-up of a completely unconfigured network until
each and every OVS can directly communicate with everyone
else. In other words, the convergence time is the time from
the startup until all RCAs reach a stable state in a given
network. In this experiment, during and after the convergence,
the network is not structurally altered (no new nodes are added,
no nodes are removed, no new links are added/removed).
Full convergence is a very conservative estimate: usually,
nodes can communicate to the controlling node much earlier
as shown in the previous experiment, using another RCA to
forward their messages to some other RCA, until these finally
reach the controller5.
In Figure 3, the RCAs reach a stable state after about 20
seconds (resp. 70,130, and 150 seconds) for a network of 50
nodes (resp. 100, 150, and 200 nodes) when the Linearization
algorithm is used. With STP whose convergence time equals
bootstrapping time, RCAs reach a stable state after 32 seconds
on average (in Figure 2). After this time, the network has fully
converged, i.e. all keep-alive messages exchanged after the
convergence are without effect, as long the topology remains
unchanged.
D. Handling Network Link Failure
We also tested the capability of the proposed solution to
handle network dynamics, e.g. due to link failures. Specif-
ically, we tested how much time it takes to resume the
control plane connectivity for those nodes affected by link
failures occurred in the network. In this case, we compare the
5The constructed CP using [7] is not a single-rooted tree (like STP) but
a structurally adjustable topology, supporting path diversity. This however
comes at a price of higher yet still realistically usable convergence times.
performance of the Linearization algorithm with RSTP [11],
which is an extension of the original STP proposed to handle
network dynamics.
We first report the evaluation results for RSTP from section
2.1 of [12]. They show that in a small network, with 4to 20
nodes, and when only a single link failure occurs, it takes 1
to 5seconds to resume the connectivity of the affected nodes.
According to our literature study, no results are available for
multiple link failures when RSTP is used, but we expect the
time to be larger than what is reported in [12]. This would be
evaluated in our future study through measurements.
To perform our test on the Linearization algorithm, rather
than breaking only a single link, we randomly selected a
number of links, removed them from the network, and then
measured the time until the control plane connectivity is fully
re-established, referred to as resuming time. We measure the
resuming time for two different network sizes, 100 and 150
nodes, and for different fractions of link failures of the links,
namely 10% and 20%. The results are depicted in Figure 4. We
observe that, in the median, less than 8s are needed with 10%
link failures in both network size cases to fully resume the
control plane communication, while with 20% link failures,
around 10s are needed for both network size cases.
These results indicate that by selecting an appropriate
routing scheme, we can provide fast bootstrapping time and
fast resuming time, even when multiple link failures happen.
We should mention that further study is required to completely
understand the impact of the selected routing mechanism on
these performance metrics.
V. RE LATE D WOR K
Establishing a CP for a mobile network is challenging.
In current generations, the network infrastructure is rather
static and CP setup is done by management with professional
expertise. If network failures and mistakes happen, usually on-
site repairing and re-configurations are required. This problem
becomes more severe if we have much denser small cells in
5G [13]. In order to support various network services, network
protocols have to be pre-installed on the network devices. For
example, OSPF [14] and BGP [15] have to be configured on
routers. According to specific requirements, engineers have to
prepare the configurations for the devices. In future, radically
novel in emerging use cases is the unforeseeable service
patterns at the moment of network deployment in 5G. This
makes pre-planning and static methods inefficient.
Programmability of a network infrastructure facilitates rapid
deployments of network services and fine-grained network
flow control. However, a critical prerequisite is the availability
of a functioning control network. Such a control network
so far is not autonomous and cannot be established without
human intervention. Hence, in 5G with high dynamics, CP’s
autonomy is even more critical than before.
IETF already recognized the CP connectivity issue [16]. It
proposes autonomic control plane by including an existing
IPv6 routing protocol. Its idea is to provide a hidden and
logically separated control plane for traditional IP networks.
50 100 150 200
Number of Nodes
0
5
10
15
20
25
BootStrapping Time (s)
Fig. 1: Bootstrapping time of [7]
50 100 150 200
Number of Nodes
28
30
32
34
36
38
40
Time (s)
Fig. 2: Bootstrapping (Convergence) time
of STP
50 100 150 200
Number of Nodes
0
200
400
600
800
1000
Convergence Time (s)
Fig. 3: Convergence time of [7]
100 150
Number of Nodes
0
2
4
6
8
10
12
14
Resuming Time (s)
10%
20%
Fig. 4: Resuming time of [7]
In reality, the OVS implementation [10] also recognizes the
CP establishment issue where standalone STP in the linux
networking stack is used to establish an in-band CP connec-
tivity. However, it does not achieve the CP’s autonomy while
out-of-band capability (i.e. linux stack) is implicitly utilized.
In [17], in-band control is built based on hybrid network
nodes where DHCP is used to locate the controlling point.
Restoration of the CP connectivity relies on calculating alter-
native paths, and protection of the control channel relies on
pre-calculating one disjoint path for every controlled nodes.
One feature of this work is that queuing mechanism is in-
tegrated so as to better serve the control traffic forwarding
because of its high priority. Similarly, the work of [18]
proposed to integrate an OSPF module aside in the switch.
VI. CONCLUSION
The envisioned 5G use cases make the network topology
and network services unforeseeable. Control plane establish-
ment and maintenance become thus the key challenge because
any pre-planning and static configuration are inefficient and
unrealistic. In this paper, we proposed Aerosmith, our solution
to solve the problem. Aerosmith is responsible for handling the
effects of network dynamics, it identifies network resources
and abstracts their usages, particularly considering the pro-
grammability of the network. The proposed solution makes
the difficulties of control plane establishment and maintenance
transparent to the network developers. Our prototype validates
our idea and provides insights for the resource control at the
edge of a 5G mobile network.
ACKNOWLEDGMENT
This work was partly funded by the EU H2020 5G XHAUL
project (H2020-ICT-2014-2 671551).
REFERENCES
[1] A. Gupta and et al., “A survey of 5g network: Architecture and emerging
technologies,” IEEE access, vol. 3, pp. 1206–1232, 2015.
[2] 3GPP, “Service requirements for the 5G system; Stage 1, Technical
Specification (TS) 22.261, 3GPP, 09 2017. Version 15.2.0.
[3] J. Martins and et al., “Clickos and the art of network function virtualiza-
tion,” in Proceedings of the 11th USENIX NSDI, pp. 459–473, USENIX
Association, 2014.
[4] Y. C. Hu and et al, “Mobile edge computinga key technology towards
5g,” ETSI White Paper, vol. 11, no. 11, pp. 1–16, 2015.
[5] 3GPP, “System Architecture for the 5G System; Stage 2,” Technical
Specification (TS) 23.501, 3GPP, 12 2017. Version 2.0.1.
[6] 3GPP, “Procedures for the 5G System; Stage 2,” Technical Specification
(TS) 23.502, 3GPP, 12 2017. Version 2.0.0.
[7] M. Onus, A. Richa, and C. Scheideler, “Linearization: Locally self-
stabilizing sorting in graphs,” in Proceedings of the Meeting on Algo-
rithm Engineering & Expermiments, pp. 99–108, Society for Industrial
and Applied Mathematics, 2007.
[8] M. Caesar and et al., “Virtual ring routing: Network routing inspired by
dhts,” in SIGCOMM ’06, pp. 351–362, ACM, 2006.
[9] I. Stoica and et al., “Chord: A scalable peer-to-peer lookup service for
internet applications,” in SIGCOMM’01, pp. 149–160, ACM, 2001.
[10] B. Pfaff and et al, “The design and implementation of open vswitch.,
in NSDI, pp. 117–130, 2015.
[11] W. Wojdak, “Rapid spanning tree protocol: A new solution from an old
technology, Reprinted from CompactPCI Systems, 2003.
[12] A. Myers, E. Ng, and H. Zhang, “Rethinking the service model: Scaling
ethernet to a million nodes,” in Proc. HotNets, 2004.
[13] I. Hwang, B. Song, and S. S. Soliman, “A holistic view on hyper-
dense heterogeneous and small cell networks,” IEEE Communications
Magazine, vol. 51, no. 6, pp. 20–27, 2013.
[14] J. Moy, “Open shortest path first routing protocol (version 2), tech. rep.,
RFC 1583, Proteon, March, 1994.
[15] Y. Rekhter and T. Li, “A border gateway protocol 4 (bgp-4),” 1995.
[16] M. H. Behringer and et al., “An Autonomic Control Plane,” Internet-
Draft draft-ietf-anima-autonomic-control-plane-03, IETF, July 2016.
Work in Progress.
[17] S. Sharma and et al., “In-band control, queuing, and failure recovery
functionalities for openflow, IEEE Network, vol. 30, no. 1, pp. 106–
112, 2016.
[18] T. Omizo and et al., “Resilientflow: Deployments of distributed control
channel maintenance modules to recover sdn from unexpected failures,
IEICE TRANSACTIONS on Communications, vol. 99, no. 5, pp. 1041–
1053, 2016.
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