PLNOG14: Internet w pojazdach - Paweł Wachelka

Internet w pojazdach
Paweł Wachelka
Huawei Polska Sp. Z o.o.

Agenda
WLAN Roaming
WiFi and LTE access solution
-
-
-
- Fast Roaming
Roaming Between ACs-
Technology Introduction

WiFi ( Weak Mobility?)
TETRA overlay LTE
WiMAX (802.16m)
LTE
UMB (Already
Died)
No future
Stay at home & office?
LTE A/B
WiMAX (802.16e)
CDMA 2000 (EvDo)
UMTS (HSPA)
TD-SCDMA (HSPA)
TETRA/P25
CDMA 2000 (1X)
GSM (EDGE)
4G Beyond 4G3G2G
Technology evolution

Wi-Fi hotspot 3G/4G router
Streaming
media player
Content server
• Video server:
• Multi-path video output
• 720P/1080P HD video play
• Traditional AV interface
• Audio station report input synthesis
• Dual SIM slots
• FDD LTE•2.4G/5G
•2*2 MIMO
• Web server
•OTT app/ad (Android)
•Streaming media playing
Vehicle-mounted
video surveillance
Vehicle-mounted TV
3G/4G
LED advertising
screen
Basic capability Ad/App distributionInternet access/content
update
Storage and playing of videos
H
D
M
I
GE
Content storage/playing requirements:
•Upgradable storage space
•Reading and writing speeds that can enable
concurrent playing of streaming media
•Re-writable for over 3,000 times
Network Architecture
— All in One

NetworkTopology of the
Vehicle-Mounted Wi-Fi
Operation Solution
eSight
Agile
Controller
Big data analysis
platform
Network management, policy
management, and auditing areaService management area
Vehicle-mounted network
LogCenter
AR511Vehicle-mounted
network
Data center network
Self-provided service
content update server
Carrier
4G
Carrier
3G
Self-provided service area
VPN
gateway
Core area
Carrier network
Bus stop
Wi-Fi synchronization GPS information
synchronization
Selective opening
of Internet services
Bus station
Wi-Fi synchronization
Internet
Carrier fixed
network
Satellite

RailTransportationWi-Fi Solution
Trackside AP
Trackside AP
Trackside AP
Vehicle -mounted AP
Vehicle -mounted
AP
 Professional anti-vibration design
 IEC61373 anti-vibration standards
 Vehicle-ground fast link handover
 120 km/h+ driving speed: handover
time < 30 ms, zero packet loss
Fast handover
 Latest-generation 802.11ac vehicle-
ground products
 Vehicle-ground bandwidth 380M+
High bandwidth
Stable operating

RailTransportationWi-Fi Solution
WIFI network solution for Trains, the series APs for Metro
Video
Surveillance
Passenger
Information
Internet
access
Vehicle-mounted AP: AP9130DN
Trackside AP （AP8130DN）
Fast Roaming
120km/h Packet loss rate<1%，
Delay<30ms；
Highlight:
• 802.11ac, 1.75Gbps, MIMO 3×3,dual-
band
• External antenna
• Electromagnetic compatibility (EMC):
IEC-61000-4-2/4/5, EN50121-2/4, and
GB/T 17626
• Industrial anti-vibration M12 sockets,
complies with EN50155
Highlight:
• 802.11ac, 1.75Gbps, MIMO3×3,
• Dual-band, 2.4G switch to 5G band
• External antenna
• Dustproof and waterproof: IP67
Media
server
Vehicle-mounted AP
Vehicle-mounted
switch
Trackside AP Trackside AP
Vehicle-mounted AP
Vehicle-
mounted
switch
Media
server
Train-to-ground wireless
communication system
Train

Vehicle-Ground Fast Link Handover
Vehicle -mounted AP
1
A vehicle-mounted AP sets up links with
multiple trackside APs.
2
 As the train moves, the vehicle-mounted AP keeps monitoring
the quality of all links and sets up new communications with the
trackside AP with qualified signals.
 The vehicle-mounted AP selects the optimal link as the data
backhaul link based on the link handover algorithm.
 The vehicle-mounted AP dynamically
deletes the deteriorating link.
 Together with the optimization capability at
the forwarding plane, vehicle-ground fast
handover technology minimizes the packet loss
ratio during handovers.
3
Trackside AP Trackside AP Trackside AP

Fast Roaming
WLAN Roaming Introduction
Layer 2 and Layer 3 Roaming
-
-
-
- Roaming Between ACs

Wi-Fi Roaming Concepts
Roaming has the following
characteristics:
 Stations (STAs) can move to any
position covered by Wi-Fi in an
extended service set (ESS).
For example, STAs can move to any position
in a campus with the SSID of university.
 Running services are uninterrupted.
Services running on STAs are not interrupted
during the roaming.
 User IDs (IP addresses) do not
change.
A STA obtains an IP address when
connecting to the network, and the IP address
does not change during the roaming.
AC
AP1
Internet
Switch
Roaming path
AP2
AP1 signal strength
AP2 signal strength
A B C
Channel 6Channel 1

STA Roaming----3W1H
 Who
Who starts roaming?
 When
When does roaming start?
 How
How do STAs roam?
 What
What impact does roaming have on services?

 STAs trigger roaming.
 Signal switchover threshold: roaming
aggressiveness
STAs have different roaming aggressiveness values.
On some STAs, the roaming
aggressiveness value can be set.
Note: STA roaming depends on factors such as the driver algorithm of the STA, received signal
strength indicator (RSSI), and signal-to-noise ratio (SNR). The most important factor is the RSSI
change when the STA roams from one AP to another.
(The RSSI is used as the only roaming triggering condition in this document.)
Who?

 When the signal strength falls
below the switchover
threshold, the STA starts the
roaming process:
 Send a probe packet.
 Wait for the responses from
neighboring APs.
 Compare the signal strengths of
response packets.
AC
AP1
Internet
Switch
Roaming path
AP2
AP1 signal strength
AP2 signal strength
A B C
When?

 The STA selects the AP with the
highest signal strength and starts
roaming.
 The STA stops sending and receiving
data, and buffers data.
 The STA sends an association request to
the new AP and is associated with it.
 The STA is disassociated from the
original AP.
 The STA sends an authentication
request to the new AP.
 After being authenticated, the STA
obtains its original IP address.
12
AC
AP1
Internet
Switch
Roaming path
AP2
AP1 signal strength
AP2 signal strength
A B C
How?

In normal cases, roaming time differs depending on the
authentication mode.
 The process of open, WEP, and PSK authentication modes is short, reducing
roaming time. Therefore, these authentication modes can meet requirements for
uninterrupted services.
 The process of 802.1x authentication is long, increasing roaming time to longer
than 200 ms. Therefore, roaming in 802.1x authentication mode affects services
with high requirements on real-time transmission, such as the voice service.
Fast roaming technology is introduced to address the
limitations of long roaming in 802.1x authentication.
What?

AC
AP1
Internet
Switch
Roaming STA
AP2
SSID: HUAWEI-WLAN SSID: HUAWEI-WLAN
VLAN: 100 VLAN: 100
IP: 10.1.100.0/24 IP: 10.1.100.0/24
IP: 10.1.100.100/24
 Multiple APs are connected in a VLAN.
 STA roaming between APs is implemented in a
VLAN.
Layer 2 Roaming

AC
AP1
Internet
Switch
Roaming STA
AP2
SSID: HUAWEI-WLAN SSID: HUAWEI-WLAN
VLAN: 100 VLAN: 200
IP: 10.1.100.0/24 IP: 10.1.200.0/24
IP: 10.1.100.100/24
 APs are located in different VLANs.
 During STA roaming, user's VLAN remains
unchanged.
Layer 3 Roaming

In direct (or local) forwarding mode, Layer 3
roaming allows a STA to move from AP1 to
AP2 while retaining the original VLAN that the
STA joined. Meanwhile, the access switch
allows packets from the VLAN to pass.
1. STA1 is connected to AP1. The user VLAN of
STA2 is VLAN 1000.
2. During roaming, the AC delivers the user VLAN to
the AP. The AP adds the user VLAN ID to STA1.
3. After STA1 roams to AP2, to ensure uninterrupted
services, AP2 adds VLAN tag 1000 to packets from
STA1 and sends the packets to the upper network.
When receiving packets from STA2, AP2 still adds
VLAN tag 1001 to the packets before sending them
to the upper network.
(The AC notifies the new AP of STA information
during roaming.)
Layer 3 Roaming: direct forwarding

In tunnel forwarding mode, the AC must
retain the original VLAN that a roaming
STA joined after the STA roams to a new
AP, to implement Layer 3 roaming.
1. Before roaming, the VLAN of a STA is 1000. When a
packet from the STA passes through AP1, AP1 adds
VLAN tag 1000 to the packet and encapsulates the
packet. When receiving the encapsulated packet, the
access switch adds VLAN tag 900 to the packet and
forwards it to the AC. The AC removes VLAN tag 900
from the received packet, decapsulates the packet, and
sends it to the upper network.
2. After the STA roams to AP2, AP2 adds VLAN tag
1001 to a packet from the STA and encapsulates the
packet. When receiving the encapsulated packet, the
access switch adds VLAN tag 901 to the packet and
forwards it to the AC. The AC removes VLAN tag 901
from the received packet, decapsulates the packet,
replaces VLAN tag 1001 with VLAN tag 1000, and
sends the packet to the upper network. In this way,
services are uninterrupted.
(The AC collects and forwards STA information
during roaming.)
Layer 3 Roaming: tunnel forwarding

The issue is how to reduce the roaming time and optimize user experience.
Key negotiation
between the AP and
STAs
Roaming process and time

STA AP AC RADIUS
1: EAPOL-start
2: EAPOL-Request-Identity
3: EAPOL-Response-Identity
4: Radius-Access-Request
5: Radius-Access-Challenge
6: EAPOL-Request-Method
7: EAPOL-Response-Method
9: Radius-Access-Accept
10: EAPOL-Success
11: EAPOL-Key
12: EAPOL-Nonce
13: PTK-Nonce
14: Verify PTK and deliver GTK-Nonce.
15: Verify that the key is available.
16: Deliver PTK and GTK
to the AP.
Steps 12 to 16
Key negotiation
Steps 1 to 10
Authentication
process
802.1x Authentication
Process

STA AP AC RADIUS
1: EAPOL-start
10: EAPOL-Success
11: EAPOL-Key
12: EAPOL-Nonce
13: PTK-Nonce
15: Verify that the key
is available.
Steps 12 to 16
Key negotiation
between the AP
and STAs
Key Negotiation
Technology, Improving
the Roaming Speed

A STA is associated with AP2 and is disassociated from AP1.
After key negotiation is performed
between the AP and STAs, roaming with
WPA/WPA2+802.1x authentication takes
a long period, which is unacceptable.
802.1x authentication is complex, which makes roaming time-consuming.
To address this issue, introduce fast roaming technology for WPA2+802.1x authentication.
Roaming Process and Time
in Key Negotiation
Between the AP and STAs

Fast Roaming Implementation
 Fast roaming is applicable only when the WPA2+802.1X security policy is used.
 WLAN devices support fast roaming technology using key caching.
 STAs support fast roaming technology using key caching.
 802.1x authentication is not required.
 Only four key negotiation steps are required.
 Key caching technology caches information about PMK, so the PMK field is a must.
A STA is associated with AP2 and is disassociated from AP1.
Note: Information Element in WPA does not define the PMK (Pairwise Master Key)
field, so WPA does not support fast roaming.

Configuring Fast Roaming for STAs
 In the wireless network setting of most STAs running Windows 7, choose 802.11 settings from Advanced
settings. You can configure and check PMK caching parameters.
(By default, fast roaming is enabled.)
 To implement fast roaming, STAs must support PMK caching.

802.1x Fast Roaming
STA AP AC RADIUS
1: EAPOL-start
10: EAPOL-Success
11: EAPOL-Key
12: EAPOL-Nonce
13: PTK-Nonce
15: Verify that the key is available.
16: Deliver PTK and GTK to
the AP.
Four
handshakes
Authentication
is skipped.
×

Fast Roaming Process
Using PMK Caching
RADIUS server
New AP
AC
STA
The STA generates and
caches the PMK ID.
Original AP
Roaming to the
new AP
The AC generates and
stores the PMK ID.
7. The AC searches the storage for the PMK
ID. If the PMK ID exists, the AC allows fast
roaming.

Terms Involved in WLAN Roaming
 Home-AC (HA): The AC with which a STA is associated for the first time is the HA of the STA.
 Foreign-AC(FA): An AC to which a STA is currently connected but not the HA is an FA of the STA.
 Roam-out STA: A STA which has associated with an AC other than the HA in the mobility group is a
roam-out STA at its HA.
 Roam-in STA: A STA which has associated with an FA in the mobility group is a roam-in STA at its FA.
 Intra-AC roaming: During intra-AC roaming, a STA roams from an AP to another AP, which are
connected to the same AC.
 Inter-AC roaming: During inter-AC roaming, a STA roams from an AP to another AP, which are
connected to different ACs.
 Inter-AC fast roaming: If a STA uses 802.1x (RSN) authentication, this STA has the inter-AC fast
roaming capability.

Inter-AC Roaming
IP network IP network
Tunnel
AP1 AP2
AC1 AC2
Preroaming synchronization
1. The STA is associated with AP1
managed by AC1.
2. The STA roams to AP2 and is
disassociated from AP1. AP2 is
managed by AC2.
3. The process that the STA
roams from AP1 to AP2 is inter-
AC roaming. Before inter-AC
roaming, AC1 and AC2 must
synchronize information about the
roaming STA through a tunnel.
STA

Intra-FA Roaming
Tunnel
AP1 AP2
AC1 AC2
Preroaming synchronization 1. The STA is associated with AP1
managed by AC1.
2. The STA roams to AP2
managed by AC2 and is
disassociated from AP1. AC2
becomes the FA to which the STA
is connected.
3. The STA is associated with AP2
after inter-AC roaming. Before
inter-AC roaming, AC1 and AC2
must synchronize information
about the roaming STA through a
tunnel.
4. The STA roams to AP3 and is
disassociated from AP2. AP2 and
AP3 are managed by the same
AC (AC2). The process that the
STA is associated with AP3 is
intra-FA roaming.
AP3
STA

Inter-FA Roaming
Tunnel
AP1
AP2
AC1 AC3 1. The STA is associated with AP1
managed by AC1.
2. The STA roams to AP2 managed by
AC2 and is disassociated from AP1.
AC2 becomes the FA to which the STA
is connected.
3. The process that the STA is
associated with AP2 is inter-AC
roaming.
4. The STA roams to AP3 managed by
AC3 and is disassociated from AP2.
AC3 becomes the FA to which the STA
is connected. The process that the STA
is associated with AP3 is inter-FA
roaming. Before inter-AC roaming,
AC1, AC2, and AC3 must synchronize
information about the roaming STA
through tunnels.
AP3
AC2
IP network
STA

Roaming-Back
IP network
Tunnel
AP1 AP2
AC1 AC2
Preroaming synchronization 1. The STA is associated with AP1
managed by AC1. AC1 is the HA to
which the STA is connected.
2. The STA roams to AP3 managed
by AC2 and is disassociated from
AP1. AC2 becomes the FA to which
the STA is connected.
3. The process that the STA is
associated with AP3 is inter-AC
roaming. Before inter-AC roaming,
AC1 and AC2 must synchronize
information about the roaming STA
through a tunnel.
4. The STA is disassociated from AP3
and roams back to AP2. AP1 and AP2
are both connected to AC1 (HA). This
process is roaming-back.
AP3
STA
IP network

Copyright@2015 Huawei Technologies Co., Ltd. All Rights Reserved.
The information in this document may contain predictive statements including, without limitation, statements regarding the future financial and operating results, future product
portfolio, new technology, etc. There are a number of factors that could cause actual results and developments to differ materially from those expressed or implied in the predictive
statements. Therefore, such information is provided for reference purpose only and constitutes neither an offer nor an acceptance. Huawei may change the information at any time
without notice.
HUAWEI ENTERPRISE ICT SOLUTIONS A BETTER WAY

PLNOG14: Internet w pojazdach - Paweł Wachelka

Recommandé

Recommandé

Contenu connexe

Tendances

Tendances (20)

En vedette

En vedette (20)

Similaire à PLNOG14: Internet w pojazdach - Paweł Wachelka

Similaire à PLNOG14: Internet w pojazdach - Paweł Wachelka (20)

Dernier

Dernier (9)

PLNOG14: Internet w pojazdach - Paweł Wachelka