3G LOW THROUGHPUT
TIGO SENEGAL
PREPARED BY MAMANE SANI IBRAHIM
Agenda
1.
CONTEXT
2. PS NETWORK DIAGRAM
3. TESTS scenarios for troubleshooting
HLR-VLR Profile
4. test results, Analysis and recommendations
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CONTEXT
› 3G low throughput has been observed in Tigo
senegal network.
› A Number of actions plan have been taken:
– Feature normalization project,
– TX wan capacity expansion , etc.
› Despite above actions, 3G throughput is still low
inHLR-VLR
the network
(less than 2.5 Mbps MAC TP).
Profile
› To find out the issue, some series of tests have
been performed aiming to check Gi interface, Gy
interface impact on the throughput.
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PS NETWORK DIAGRAM
HLR-VLR Profile
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TESTS scenarios (1)
› SCENARIO 1
› This test is targeting to check how charging system
is impacting prepaid and postpaid subscribers. It is
aiming also to check if there is any impact based on
protocol type . It is why most used protocols have
been chosen (FTP, HTTP, YOUTUBE).
› FTP Download
HLR-VLR
Profile
›
›
›
›
›
from remote FTP Server
YOUTUBE (for streaming)
HTTP (For browsing )
TESTAPN used for all protocol calls
Same file size: 5 FILES of 20MB WERE DOWNLOAD
prepaid and postpaid used in parallel
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TESTS scenarios (2)
› SCENARIO 2 – not done
› This test is targeting to check how each Gi route is
impcating the throughput
› FTP Download from remote FTP Server
› YOUTUBE (for streaming)
› HTTP (For browsing )
Profileused for all protocol calls
›HLR-VLR
TESTAPN
› Same file size: 5 FILES of 20MB WERE DOWNLOAD
› 2 prepaid sims used in parallel
› Make available only one route at same time
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Scenario 1 test results
› After Scenario 1 test, it comes that the
throughput is higher with POSTPAID SIM than
PREPAID SIM whatever the protocol used (HTTP,
YOUTUBE, FTP).
HLR-VLR Profile
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HTTP Download Throughput (kbps)
with sims Postpaid/Prepaid
10 FILES WERE DOWNLOAD FROM BOTH SIMS CARDS .THE GRAPH ABOVE SHOWS A MAX
THROUGHPUT AT 1.8MBPS FROM POSTPAID SIMS.
SERVING CELL DK15947, SC=129
The Max RSCP is between -85DBM and -95DBM and ECNO between -4DB and -10DB
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YOUTUBE Throughput with sims
Postpaid/Prepaid
Two video of 5min were launched on YouTube. THE GRAPH ABOVE SHOWS A MAX
THROUGHPUT AT 1.2MBPS from postpaid sims
SERVING CELL DK15947, SC=129
The Max RSCP is between -85DBM and -95DBM and ECNO between -4DB and -10DB
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HS THROUGHPUT: same SERVEUR FTP
5 FILES of 20MB WERE DOWNLOAD AT THE SERVERS .THE GRAPH ABOVE SHOWS A MAX
THROUGHPUT AT 1.8MBPS FROM POSTPAID sims .
SERVING CELL DK15947, SC=129
The Max RSCP is between -85DBM and -95DBM and ECNO between -4DB and -10DB
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Scenario 1 test results summary
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Analysis
› Knowing that same APN (TESTAPN) has been used for
both postpaid and prepaid, it is clear that prepaid
charging policy is impacting prepaid subscribers
throughput
› the Postpaid subs proportion in march is 0.77% while
prepaid proportion is 99.23% . Based on the prepaid
proportion, it is clear that low throughput impacting
prepaid subscriber may explain the low throughput at
Network level.
HLR-VLR Profile
› the QOS profile across the network has been checked.
Actually a single QoS profile is used 8.640 MBPS in
uplink and 21 MBPS in downlink for all APNs. Therefore
low Throughput cannot be linked to the type of AP.
mars-16
Postpaid
Prepaid
Total
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24 897
3 235 728
3 260 625
recommendations
› Check how to optimize the charging Policy between DPI
(Deep Packet Inspection) platform and OCS (Only
Charging System) for Prepaid subscriber.
› Tuning RSU (Requested Service Units) by increasing it
may improve prepaid subscribers throughput. However
this exercise may affect voice calls for subscribers
with balance less than a certain threshold.
HLR-VLR
› The
RSU Profile
increasing can be done step wise followed by
assessment. Based on the result an optimal value can
be found.
› a trade-off needs to be made between the throughput
level required and the amount to be reserved by the
IN nodes.
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INTERACTION BETWEEN DPI
PLATFORM AND OCS
› DPI (Deep Packet Inspection) platform sends RSU
(Requested Service Units) to OCS (Online Charging
System).
› after checking the balance and other parameters,
OCS replies to DPI platform with GSU (Granted
Service Unit).
HLR-VLR Profile
› OCS acts as per request from DPI (Deep Packet
Inspection) as designed.
› RSU value may be too low and hence affecting the
throughput due to the number of interrogations
between the DPI and OCS.
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