Chapter 19 Mobile Train Radio Communication - LTE PDF

CHAPTER XIX =========== 0. This chapter covers basic technical information of Long Term Evolution (LTE), Evolved Packet Core (EPC) and LTE based Mobile Train Radio Communication System. This document is based on Specifications of LTE and FRMCS developed by 3rd Generation Partnershi...

CHAPTER XIX =========== 0. This chapter covers basic technical information of Long Term Evolution (LTE), Evolved Packet Core (EPC) and LTE based Mobile Train Radio Communication System. This document is based on Specifications of LTE and FRMCS developed by 3rd Generation Partnership Project (3GPP) and International Union of Railways (UIC). 1. With GSM, ERA and UIC added extra functionality and called it GSM for Rail, GSM-R. So far the indication is that UIC will try a different approach with LTE and try to get as much functionality into the regular LTE standard, thereby not needing to add extra specific functionality for railways. There are some indications that LTE will end up with more functionality that is valuable to the railway industry than GSM did in its time. The Mobile Train Radio Communication System with LTE technology is in the development stage. 2. The International Union of Railways, UIC a global organization for Railway has set up Future Rail Mobile Communications System (FRMCS) project to prepare the necessary steps towards the introduction of a successor of GSM-R. The Future Railway Mobile Communication System - FRMCS has been prepared by UIC in order to have a Mobile Train Communication System based on LTE. 3. Limitations of GSM-R:- ====================== 1. As the communication demands increased and the capabilities of electronic devices evolved, it has become necessary to support data communication as much as voice communication. GSM-R does not provide packet-switched transmission. Therefore, data communication must be delivered by Circuit-Switched Data (CSD), which cannot assign the network resources based on the actual demand. This means that data is transmitted over virtual circuits, just like voice frames. Being bursty in nature, data sources send varying amounts of data at irregular intervals. Such a bursty transmission does not fit well into a fixed circuit provided by GSM-R. As a result, circuits are often underutilized and network resources are wasted. 2. GSM-R is becoming an obsolete technology. The predicted obsolescence of GSM-R is by 2030. 4. LTE: Long Term Evolution:- ========================== 3. Long Term Evolution (LTE) is the latest family of mobile communication standards (4G) developed by 3rd Generation Partnership Project (3GPP). The main requirements for the new access network are high spectral efficiency, high peak data rates, Short round trip time as well as flexibility in frequency and bandwidth. 5. Components of Long Term Evolution (LTE):- ========================================= 4. The key components of the LTE network sub-system are mentioned below: 1. **E-UTRAN: eNodeB (Equivalent of BSS in GSM-R**) (Evolved Universal Terrestrial Radio Access Network) Serving Gateway (S-GW): ======================= Packet Data Network Gateway (PDN-GW): ===================================== Mobility Management Entity (MME): ================================= Home Subscriber Server (HSS): ============================= 6. **Policy and Charging Rules Function (PCRF):** 7. **Policy and Charging Enforcement Function (PCEF):** IP Multimedia Core Network Subsystem (IMS): ===========================================  6. Features of Long Term Evolution (LTE):- ======================================= 5. LTE is fully packet-switched IP-based mobile communication standard from 3GPP. Both real time services and datacom services will be carried out by IP protocol. LTE network assigns the network resources to users and applications depending on the actual transmission demand. 6. LTE introduces a simplified core network called Evolved Packet Core (EPC) with fewer elements than in the legacy standards. 7. The new access solution, LTE, is based on OFDMA (Orthogonal Frequency Division Multiple Access) and in combination with higher order modulation (up to 64QAM), large bandwidths (up to 20 MHz) and spatial multiplexing in the downlink (up to 4x4) high data rates can be achieved. Frequency: ========== 9. Spectral Flexibility: ===================== 9. E-UTRA shall operate in spectrum allocations of different sizes, including 1.4, 3, 5, 10, 15 and 20 MHz as per 3GPP/ETSI in both the uplink and downlink. Operation in paired and unpaired spectrum are supported. 10. The system shall be able to support content delivery over an aggregation of resources including Radio Band Resources (as well as power, adaptive scheduling, etc) in the same and different bands, in both uplink and downlink and in both adjacent and non-adjacent channel arrangements. A "Radio Band Resource" is defined as all spectrum available to an operator. 10. Peak data rate (Spectral Efficiency): ===================================== 11. Instantaneous downlink peak data rate of 100 Mb/s within a 20 MHz downlink spectrum allocation (5 bps/Hz) 12. Instantaneous uplink peak data rate of 50 Mb/s (2.5 bps/Hz) within a 20MHz uplink spectrum allocation) 13. The highest theoretical peak data rate on the transport channel is 75 Mbps in the uplink, and in the downlink, using spatial multiplexing, the rate can be as high as 300 Mbps. 11. **Transmission Latency:** The LTE (4G) supports low transmission latency both in User plane and Control Plane. The time taken for data to travel in the air interface between UEs (mobile) to eNodeB (base station) is achieved to be less than 5 ms (User Plane) and time taken for a UE to switch from standby IDLE state to ACTIVE state is less than Control-plane capacity : ======================== 13. Mobility: ========= 14. E-UTRAN should be optimized for low mobile speed from 0 to 15 km/h. 15. Higher mobile speed between 15 and 120 km/h should be supported with high performance. 16. Mobility across the cellular network shall be maintained at speeds from 120 km/h to 350 km/h. 14. Coverage: ========= -- -- -- -- -- -- -- -- -- -- 15. Enhanced Multimedia Broadcast Multicast Service (MBMS) : ======================================================== 17. While reducing terminal complexity: same modulation, coding, multiple access approaches and UE bandwidth than for unicast operation. 18. Provision of simultaneous dedicated voice and MBMS services to the user. 19. Available for paired and unpaired spectrum arrangements. 16. Co-existence and Inter-working with 3GPP Technology : ===================================================== 20. Co-existence in the same geographical area and co-location with GERAN/UTRAN on adjacent channels. 21. E-UTRAN terminals supporting also UTRAN and/or GERAN operation should be able to support measurement of, and handover from and to, both 3GPP UTRAN and 3GPP GERAN. 22. The interruption time during a handover of real-time services between E-UTRAN and UTRAN (or GERAN) should be less than 300 msec. 17. Architecture and migration : ============================ 23. Single E-UTRAN architecture 24. The E-UTRAN architecture shall be packet based, although provision should be made to support systems supporting real-time and conversational class traffic 25. E-UTRAN architecture shall minimize the presence of "single points of failure" 26. E-UTRAN architecture shall support an end-to-end QoS 27. Backhaul communication protocols should be optimized 18. Radio Resource Management requirements : ======================================== 28. Enhanced support for end to end QoS 29. Efficient support for transmission of higher layers 30. Support of load sharing and policy management across different Radio Access Technologies 19. Complexity : ============ 31. Minimize the number of options 32. No redundant mandatory features 20. LTE is the latest family of mobile communication standards. Hence, it has much lower obsolescence risk than any of the previous standards. Mobile Train Radio Communication System (LTE) :- ================================================ LTE System Architecture for Indian Railways:- ============================================= 1. Passenger Safety & Service: - Advanced Signalling systems like European Train Control System (ETCS) Level 2/Train Collision Avoidance System (TCAS). - Emergency communications from train to control, train to stations and between train to train, etc. - Increased carrying capacity (throughput) Advanced signaling systems allow more trains to run across a given point or segment of the track which effectively increase the carrying capacity (throughput) of the same fixed civil and electrical infrastructure. 2. Live surveillance camera feeds from trains will ensure security of passengers coupled with video analytics, this can help in prevention and detection of crime, not only in Indian Railways network but also outside in the peripheral areas. 3. Internal improved Railway management: - Staff communication system. - Remote monitoring of Railways asset to improve their availability. 4. Indian Railway envisages following applications/facilities which will fuel growth in data usage on deploying LTE technology: i. Indian Railway Automatic Train Protection System (IRATP) through Train Collision Avoidance System (TCAS) which is planned for up gradation to ETCS Level 2 in future or any other similar systems as specified by Indian Railways. ii. Mission Critical Push To Talk (MC PTT) application iii. Video Surveillance System in locomotives for Level Crossing Gate/ Tunnels/ Bridges. iv. Onboard Passenger Information System (PIS) consisting of passenger information display and passenger announcement system. v. Internet of Things (IoT) based Asset reliability monitoring. vi. Onboard Video Surveillance System (VSS) for Passenger Security. vii. Broadband Internet on Running Train (Onboard Wi-Fi facility through LTE). 10. TRAI Frequency Band Allocation:- ================================ LTE FDD System Throughput :- ============================ --------- -- -- -- -- -- ------ 1.4 MHz 4.4 3 MHz 11.1 5 MHz 18.3 10 MHz 36.7 15 MHz 55.1 20 MHz 75 --------- -- -- -- -- -- ------ Uniform Numbering Scheme for Mobile Communication Network for Indian Railways :- ================================================================================ A. All mobile users in the LTE network must be assigned a certain addresses or identities in order to identify, authenticate and localize them. The following numbers and identities are assigned for administration of each mobile station in the network. i. IMSI : International Mobile Subscriber Identity - Mobile country code (MCC): The MCC is the first field of the IMSI and is three digits in length and identifies a country. - Mobile network code (MNC): The MNC is the second field of the IMSI, it is two or three digits in length and is administered by the respective national numbering plan administrator. - Mobile subscription identification number (MSIN): The MSIN is the third field of the IMSI, it is up to 10 digits in length, and is administered by the relevant MNC assignee to identify individual subscriptions. ii. MS ISDN : Mobile Subscriber International Subscriber Directory Number - Country Code (CC), up to three digits; - National Destination Code (NDC), typically two or three digits; - Subscriber Number (SN), a maximum of 10 digits.  19.14 Adaptation of LTE on Indian Railways:- ============================================