Convert Latitude/Longitude to Decimal
Degrees, Minutes, Seconds to/from Decimal Degrees The form below allows you to convert Latitude and Longitude information between decimal format and degree/minute/second (DMS) format. This is useful when finding distances. Here's the basic equation:
LAPD protocol
All messages sent on the A-bis interface use the LAPD
protocol that enables reliable transmission of information. LAPD provides two
kinds of transfer modes: Unacknowledged info transfer with no guarantee that
the information frame is successfully delivered to the addressee, and
acknowledged information transfer, where each signal is acknowledged, and the
system makes sure that the frame has reached the destination successfully. Only
measurement reports use unacknowledged information transfer.
A flag, 01111110 (h'7E), delimits a frame. The one flag
is enough between consecutive frames. The receiving entity looks for the flag
01111110 to synchronize on the start of a frame.
TEI and SAPI are used to access the right entity and
right function at the receiving end.
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SAPI
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is the address used to access different
functions, such as TRXC, CF and Layer 2 management procedures, within one
physical entity. The CF (Central Function) link is used in RBS 2000 for
common management functions for the TG, for example BTS software download.
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TEI
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is the address used to access different
physical entities such as an individual TRX for radio signaling.
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Two data link types are defined for each TEI. The data
link types and their corresponding SAPI are:
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SAPI=0
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is used for the Radio Signaling Link (RSL).
This link is used for supporting traffic management procedures mainly for
circuit switched traffic. Signalling on Packet Data Channels (PDCH) is not
carried by the RSL link. One link is required per TRX defined.
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SAPI=62
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is used for the Operations & Maintenance
Link (OML). This link is used for supporting network TRXC management
procedures.
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The physical entities (TRX) that BSC communicates with at
the BTS, via data links, are referred to as Terminal Equipment. A TEI/SAPI
pair, unique within each physical connection identifies each data link. Each
physical connection can support a number of data links.
Each TRX have one OML and one RSL signaling link.
Additionally there is a CF signalling link to the DX function in the RBS2000.
These links use the LAPD protocol:
- The CF link
is identified by the TEI value (configurable) and SAPI=62.
- The OML link
is identified by the TEI value for the TRX and SAPI=62.
- The RSL link
is identified by the TEI value for the TRX and SAPI=0.
- The TRX TEI
value is defined by the TRX position in the RBS cabinet.
The LAPD concentrator receives messages from several TRXs
and sends these messages on one 64 kbit/s Abis time slot to BSC. The LAPD
concentrator also receives messages on this Abis time slot from the BSC and
distributes them to the TRXs.
Without LAPD Concentration and LAPD Multiplexing each 64
Kbits/s A-bis time slot can support signalling for only one TRX.
With LAPD Concentration each 64 Kbits/s A-bis time slot
can support signalling for up to four TRXs. The allocation of bandwidth between
the different TRXs sharing a 64 kbit/s A-bis time slot is dynamic: the concentration
is implemented as separately addressed messages which are sent over the common
path. This means both transmission delays are minimized - LAPD Concentration is
superior to LAPD Multiplexing when it comes to delays and thoughput
performance.
GSM PHASES
In the late 1980s, the groups
involved in developing the GSM standard realized that within the given
time-frame they could not complete the specifications for the entire range of
GSM services and features as originally planned. Because of this, it was
decided that GSM would be released in phases with phase 1 consisting of a
limited set of services and features. Each new phase builds on the services
offered by existing phases.
Phase 1
Phase 1 contains the most common
services including:
·
Voice telephony
·
International roaming
·
Basic fax/data services (up to 9.6
kbits/s)
·
Call forwarding
·
Call barring
·
Short Message Service (SMS)
Phase 1 also incorporated
features such as ciphering and Subscriber Identity Module (SIM) cards. Phase 1
specifications were then closed and cannot be modified.
Phase 2
Additional features were
introduced in GSM phase 2 including:
·
Advice of charge
·
Calling line identification
·
Call waiting
·
Call hold
·
Conference calling
·
Closed user groups
·
Additional data communications
capabilities
Phase 2+
The standardization groups have
already defined the next phase, 2+. This program covers multiple subscriber
numbers and a variety of business oriented features. Some of the enhancements offered
by Phase 2+ include:
·
Multiple service profiles
·
Private numbering plans
·
Access to Centrex services
·
Interworking with GSM 1800, GSM 1900
and the Digital
Enhanced Cordless
Telecommunications (DECT) standard Priorities and time schedules for new
features and functions depend primarily on the interest shown by operating
companies and manufacturers and technical developments in related areas.
Phase 2++ This
phase includes sophisticated enhancements to the radio interface including:
·
Enhanced Datarates for Global Evolution
(EDGE), a new modulation method which increases capacity on the air interface.
·
Customized Application for Mobile
Enhanced Logic (CAMEL), a standard, governing IN service access while roaming
internationally.
·
High Speed Circuit Switched Data
(HSCSD), a method of delivering higher data rates per subscriber by allocating
an increased number of time-slots per call.
Types of Alarm
TGC FAULT No active TGC application exists in the Transceiver
Group.
PERMANENT FAULT A managed object is classified as being permanently
faulty when fault situations have occurred, and have been cleared, a certain
number of times within a certain period of time. Manual intervention is
required to bring such equipment back into operation.
LOCAL MODE The BTS equipment is in Local Mode or the BTS equipment
has changed from Local to Remote Mode and a fault exists in the communication
link between the BSC and the BTS. Communication between the BSC and the BTS is
not possible.
LMT INTERVENTION Local maintenance activities are being performed in the
BTS.
LOOP TEST FAILED Test of the traffic carrying capabilities of the TS has
failed.
BTS INTERNAL There is a fault internal to the BTS.
MAINS FAILURE There is a fault in the power supply to the BTS or one
or more items of equipment within the BTS. Battery backup (where available) is
in use. Escalation may occur if corrective action is not taken.
BTS EXTERNAL There is a fault external to the BTS.
OML FAULT There is a fault in the communications link between the
BSC and BTS.
ABIS PATH UNAVAIL No transmission device exists between the BSC and BTS.
CON QUEUE CONGESTION At least one of the LAPD Concentrator concentration
outlet queues has reached an unacceptable filling level.
TS SYNC FAULT Synchronization lost on uplink or downlink TRA or PCU
channels.
FORLOPP RELEASE A fault has occurred within the BSC software leading to
a Forlopp release. Automatic recovery procedures are taking place. Report to
your Ericsson Support Office. Alternatively, this alarm is issued as an
advisory following a command ordered Forlopp release of a TG. In either case,
the alarm is automatically ceased following successful recovery.
OPERATOR CONDITION A condition has arisen due to operator intervention.
How to calculate Peak Data Rate in LTE
The Peak Data rate of LTE is about 400Mbps?
It’s in a simple way to calculate date rate in
LTE.
First: Assume That 20 MHz channel
bandwidth, normal CP, 64QAM and 4x4 MIMO technology are used.
Second: Calculate the number of
resource elements (RE) in a subframe with 20 MHz channel bandwidth:
12 subcarriers x 7 OFDMA symbols x
100 resource blocks x 2 slots= 16800 REs per subframe. Each RE can carry a
modulation symbol.
Third: Assume 64 QAM modulation and no coding, one
modulation symbol will carry 6 bits.
The total bits in a subframe (1ms)
over 20 MHz channel is 16800 modulation symbols x 6 bits / modulation symbol =
100800 bits. So the data rate is 100800 bits / 1 ms = 100.8 Mbps.
Fourth: with 4x4 MIMO, the
Peak Data rate goes up to 100.8 Mbps x 4 = 403 Mbps.
EPG on Juniper
Based on the
Juniper M320 or M120 router, the EPG supports Physical Interface Cards (PICs)
of the following types:
·
EPG services PIC: All EPG application software entities run
on the EPG services PIC. These entities consist of Globe Session Controller
(GSC), SGW Session Controller (SSC) and PGW Session Controller (PSC) for
Control Plane, and Packet Processor (PP) and L2TP Packet Processor (TPP) for
User Plane. The EPG services PIC is PB-GGSN3 Services PIC.
·
Network interface PIC: The network interface PIC provides 1GE or
10GE Ethernet connectivity for the EPG.
·
Standard services PIC: the standard services PIC runs
platform-generic services, such as encapsulation and decapsulation of user
payload into Generic Routing Encapsulation (GRE) or IPsec tunnels.
For EPG on
Juniper, the following Network Interface PICs are supported:
·
2-Port Gigabit Ethernet PIC
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4-Port Gigabit Ethernet PIC
·
8-Port Gigabit Ethernet PIC
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10-Port Gigabit Ethernet PIC
·
1-Port 10Gigabit Ethernet PIC
Note: The 10-Port Gigabit Ethernet PIC
is only used by the EPG on M320 router.
Both M120
and M320 routers contain 4 and 8 Flexible PIC Concentrators (FPCs)
respectively, which are used for the PIU container installation. In addition,
two compact FPC (cFPC) slots are available on the M120 router for transport
purposes only.
A single FPC
or a cFPC slot in the EPG on M120 router has a maximum throughput of 10 Gbps
full duplex. A single FPC slot on the
M320 router has a maximum throughput of 16 Gbps or 20 Gbps full duplex.
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