2G-4G Signaling Mastery for Interviews: CS, PS, LTE & VoLTE

Name: 2G-4G Signaling Mastery for Interviews: CS, PS, LTE & VoLTE
Rating: 4.3 (14 reviews)

Unlock telecom careers: Dive into signaling procedures & call flows across mobile generations, from GSM to VoLTE

Created byCore & IMS Learning

Last updated 2/2024

English

English [Auto],

What you'll learn

Understand signaling in 2G to 4G networks, focusing on CS, PS, LTE, and VoLTE technologies.
Master the IMSI attach/detach and authentication processes across mobile generations.
Navigate complex call flows for mobile-originated and terminated calls efficiently.
Implement secure ciphering and encryption techniques in mobile communications.
Execute PDP context activation, modification, and deactivation in PS networks.
Perform EPC attach, bearer establishment, and tracking area updates in LTE.
Facilitate smooth VoLTE calls and manage IMS registration and third-party integrations.
Diagnose and resolve common signaling issues in 2G, 3G, and 4G networks.

Course content

4 sections • 44 lectures • 8h 29m total length

Basic Procedures in CS (Circuit Switched) Core Network4:25
Master the basic procedures of the CS core network, covering IMSI attach, authentication, authorization check, location update, and TMSI allocation.
Mastering Mobile Connectivity: IMSI Attach Essentials5:41
Explore IMSI attach fundamentals, showing how a subscriber sends an attach to become idle and access the network, including authentication, location update, and sleep mode.
Securing the Network: Authentication Deep Dive26:52
The lecture explains subscriber authentication using triplets—random number, signed response, and cipher key—generated by the authentication center with A3/A8, using the SIM key and IMSI, validated by MSC, HLR, and UE.
Ensuring Privacy: The Ciphering Process Unveiled6:15
The ciphering workflow begins as the authentication center sends triplets. The MSK server uses the A8 algorithm to generate the cipher key and enable data ciphering via A5.
Optimizing Network Resources: The Purge MS Protocol2:09
Explain how the purge mobile station message from the MSC to the HLR deletes subscriber data from the MSK server and flags the mobile as not reachable until IMS attach.
Navigating Network Mobility: Advanced Location Update Strategies9:46
Explain how a mobile initiates a location update when moving between location areas; the MSC server uses map protocol over tcp/sccp to update the HLR and fetch subscriber data.
IMSI Attach explained1:10
Explore how IMSI attach initiates a location update as a mobile powers on, with the MSC, VLR, and HLR updating or inserting subscriber data and confirming the update.
Seamless Network Departures: IMSI Detach Explained1:18
Learn how IMSI detach signals when a user switches off, as the mobile sends a detach message, the MSC marks the subscriber detached, and an MS attach restores status.
Keeping Connected: The Art of Periodic Location Updates2:06
Examine the periodic location update mechanism, where a timer triggers a location update request to the MSK server to keep the user reachable, and detaches when idle for 30 minutes.
Dual-Mode Mastery: Combined Attach Procedures1:49
The combined attach procedure authenticates the subscriber on the MSC, updates location on CS and PS via the SGSN, and retrieves the profile from the HLR for future UE transactions.
Location Precision: Independent Update Techniques1:29
Explain the independent location update: when a subscriber calls, the MSC checks the HLR profile, triggers a location update if incomplete, and the HLR inserts subscriber data.
Data Synchronization: Recovery Location Update Insights1:50
Examine the data recovery procedure during call termination, where MSCs, HLR, the MSI server, and XR exchange roaming numbers and restore location updates to enable inter-MSC call setup.
Global Roaming Unlocked: Location Update Mechanisms2:49
Master roaming location updates and how home and visited networks verify permissions. Learn how MSCs, HLR, and VLR exchange subscriber data and handle visitor subscribers.
Voice in the Digital Age: MO/MT Call Signaling1:04:41
Explore how a MO/MT voice call is established in 2G networks from service requests and authentication to call setup, radio access, roaming, and inter-MSC signaling.
Texting Redefined: SMS Call Flow Dynamics15:59
Describe sms call flow dynamics from RRC setup, CM service requests for SMS, through MSC authentication and SMS center routing, to paging and delivery outcomes.
LTE to Legacy: CSFB Call Flow for Seamless Transition42:00
Learn css fallback and csfb call flow that lets a 4g subscriber drop to 2g/3g for voice, coordinated by mme, msc, and epc, and ims integration enables voice on 4g.

Gateway to the Internet: PS Core Attach Procedures16:01
Explore PS core attach procedures that register a user, authenticate with SGSN/HLR, allocate a PDP context, and enable data exchange with external packet networks.
Network Handovers: Managing SGSN Changes4:48
Explore how a new SGSN handles handover by obtaining IMS and authentication parameters from the old SGSN to perform local authentication and complete the attach sequence with HLR updates.
Unified Connectivity: CS & PS Core Combined Attach16:35
Discover how a device performs a combined attach to cs and ps networks in 2g/3g, enabling voice calls and data sessions via sgsn and msc with authentication and hlr updates.
User-Initiated Network Exit: Detach Procedures Demystified13:19
This lecture covers detach procedures in mobile signaling: who can trigger detach, how PDP contexts are deleted, cancel location, and CS/PS detach flows with radio channel release.
Administrative Sign-offs: Understanding HLR-Initiated Detach1:15
Understand how an HLR-initiated detach updates the subscriber profile on the SGSN, issues cancel location to the old SGSN, and handles reattach after routing area update.
Data Housekeeping: The Purge Procedure in PS Core4:46
after detach, the SGSN can either retain mobility management and PDP contexts for a short delay to save signaling, or delete them all at once and purge the HLR later.
Activating Data Sessions: PDP Context Essentials22:50
Explore PDP context activation signaling, including APN selection, IP address allocation, PCC rules, and QoS negotiation, with diameter protocol, and online charging via OCS and DNS lookups.
Tailoring Data Services: PDP Context Modification3:07
Modify a PDP context by downgrading the quality of service, detailing the signaling flow from UE to SGSN to GSN and RNC, and final acceptance.
Maintaining Active Sessions: PDP Context Management7:21
Analyze an PDP context with DPI to assign Twitter (20) and WhatsApp (10) rating groups. The GSN requests OCS credits, allocates quotas, and enforces limits, dropping traffic when balance ends.
Concluding Data Sessions: PDP Context Deactivation2:44
Conclude a PDP context by the SGSN deleting the PDP context after detachment, coordinating with the GGSN and PCF via credit control to terminate the session and release radio bearers.
Optimizing Data Routing: RA Update Signaling8:51
Requesting Network Services: PS Core Service Signaling3:35
Explain how a device moves from idle to connected via a service request in ps core signaling, authenticates with sgsn, reserves radio resources, and updates pdp context for qos.
Reaching the Unreachable: Paging Procedures in PS Core5:20
Learn how the PS core uses paging to wake idle users in 3G and 2G, with SGSN, RNC/BSC signaling, paging requests, and transitions to connected/ready to receive downlink data.

The Gateway to 4G: EPC Attach Procedures Uncovered8:32
Explore the gateway to 4g by detailing epc attach procedures: attach request, mutual authentication and security, location update, and eps bearer establishment, including cs fallback.
Fortifying the Network: Authentication in EPC Explained19:03
Discover how authentication, integrity, and encryption fortify the EPC, using master keys to derive cipher and integrity keys and generate NAS, RRC, and eNodeB security keys for secure air-interface communications.
Navigating the 4G Landscape: Tracking Area Update Mastery9:08
Master signaling to establish an end-to-end eps bearer from tracking area update through S1 and S5 bearers, exchanging tunnel endpoints between eNodeB, S gateway, and P gateway.
Enabling High-Speed Data: Bearer Establishment in EPC5:48
Explore how high-speed data bearer establishment follows authentication and identity checks, including IMEI/ME validation, EIR whitelisting, and updating location with the HSS to manage and delete old EPS bearers.
Graceful Network Exits: Detach Signaling in EPC Demystified7:19
Explore how a detach request triggers EPC-wide cleanup, deleting sessions and bearers, as UE powers down and signaling traverses through MME, HSS, and gateways to PCF.

Foundation of VoLTE: IMS Registration Procedures Unveiled32:00
Learn how IMS registration unfolds from SIP register messages through proxy and interrogating CSCFs to the HSS, including IMPI, IMPU, UE IP address, and the 401/200 authentication flow.
Beyond Basic Connectivity: IMS 3rd Party Registration Insights11:08
Explore IMS third party registration via the MTL application server to update the user profile and reveal originating and terminating services handled by the serving call session control function.
Real-Time Notifications: Mastering IMS Subscription Events7:02
The user equipment registers on the epc and ims network and subscribes to the registration state event via sip subscribe, enabling ims notifications through the proxy and serving csf.
VoLTE Calls Demystified: MO Call Flow Explained23:35
Explain the sip invite message structure with sip part and sdp offer, and outline high-level ims/volte call flow, covering codec negotiation, amr wideband, and default and dedicated bearers.
Call Flow Signaling messages with IMS Nodes23:29
Trace the IMS call flow from SIP invite to 100 trying, 183 session progress, and 200 ok, via proxy and interrogating CSCF, HSS, MTAS, ENUM, and bearer establishment.
Optimizing VoLTE Quality: PCRF Interaction in Call Flow23:04
Explain how the PCRF and IMS interact to reserve a dedicated bearer via the PCF using 183 session progress, enabling QoS and early call setup.
Enhancing VoLTE Services: IMS Dedicated Bearer Establishment13:27
Enhance VoLTE services by detailing the dedicated bearer establishment, linking the p-gw and s-gw through s5 and s1 tunnels, and configuring qci, bearer ID, and rrc reconfiguration.
SRVCC Flow in a high level view8:37
Track the high level srvcc flow for a VoLTE call as a user moves from 4g to 3g, with msc and mme signaling and resource reservation across epc and cse.
SRVCC Flow Preparation phase13:26
Explore the SRVCC preparation phase and signaling flow, including measurement reports, resource reservation, and the handover setup from 4G to 3G with MSC, SGSN, and IMS coordination.
SRVCC Flow Execution phase3:02
During the srvcc execution phase, 3g handover completes from ue to msc via node b, with ps to cs complete and bearer deactivations, followed by 3g voice and data sessions.

Requirements

Basic Understanding of Telecommunications
Technical Background

Description

Embark on a transformative journey through the intricate world of telecommunications signaling with our meticulously crafted course, "2G-4G Signaling Mastery for Interviews: CS, PS, LTE & VoLTE." Designed to bridge the gap between theoretical knowledge and real-world application, this course offers a deep dive into the signaling procedures and call flows that are the backbone of mobile communications.

Why This Course?

In an era where mobile technology evolves at lightning speed, understanding the foundations of mobile network signaling from 2G to 4G is crucial for professionals aspiring to excel in the telecommunications industry. Whether you're preparing for a pivotal job interview, seeking to upgrade your skills, or aiming to grasp the complexities of CS (Circuit Switched), PS (Packet Switched) networks, LTE, and VoLTE technologies, this course is your gateway to success.

What You Will Learn:

Fundamentals of Signaling: Explore the essential concepts of signaling in mobile networks, including the role of IMSI, authentication, ciphering, and location update procedures.
2G and 3G Networks: Gain insights into GSM and UMTS architectures, focusing on their respective CS and PS core networks' signaling and call flow mechanisms.
LTE Evolution: Unravel the complexities of 4G LTE networks, understanding the EPC (Evolved Packet Core) and the pivotal role of signaling in high-speed data and voice services.
VoLTE and IMS: Delve into the world of Voice over LTE, exploring IMS registration, call flows, and the seamless integration of voice services over LTE networks.
Real-World Applications: Learn through practical examples, detailed diagrams, and flowcharts that illustrate the signaling paths and procedures, preparing you for real-world challenges.
Interview Readiness: Equip yourself with the knowledge and confidence to tackle technical interviews, with insights into the most commonly asked questions and scenarios in the telecom sector.

Who Should Enroll?

This course is ideal for telecommunications engineers, network professionals, students, and anyone keen on mastering the signaling aspects of mobile communications. Whether you're aiming to kickstart your career, transition into the telecom sector, or enhance your technical expertise, this course provides the knowledge and tools to achieve your goals.

Unlock Your Potential:

Join us on this journey to demystify the complex world of mobile network signaling. Equip yourself with the skills to not just understand but also to innovate and excel in the fast-paced telecom industry. Enroll now and take the first step towards securing your place in the future of telecommunications.

Who this course is for:

Telecommunications Professionals
Engineers looking to expand their knowledge on the signaling aspects of 2G, 3G, and 4G technologies
Students pursuing degrees in telecommunications, computer science, electrical engineering, or related fields.

2G-4G Signaling Mastery for Interviews: CS, PS, LTE & VoLTE

What you'll learn

Explore related topics

Course content

Basic Procedures in CS (Circuit Switched) Core Network16 lectures • 3hr 10min

Call Flow Procedures in PS (Packet Switched) Core13 lectures • 1hr 51min

Evolved Packet Core (EPC) Call Flow Procedures5 lectures • 50min

IMS VoLTE: Advanced Communication Procedures10 lectures • 2hr 39min

Requirements

Description

Who this course is for: