Optimized train solution
View Patent ↗The use of wireless backhaul poses special challenges for in-vehicle base stations. Users that are connected to an in-vehicle base station expect continuous service, even as the in-vehicle base station passes in and out of different wireless backhaul coverage zones, such as when a train passes from a train station with good coverage to a tunnel with poor coverage. The base station thus needs seamless backhaul handover. A system that enables an in-vehicle base station to receive continuous service across different backhaul coverage zones is needed. To solve this problem, a system enabling handover is described. The system involves double-tunneling mobile device data packets in an ESP-UDP IPsec tunnel encapsulated in a GTP-U tunnel. Traffic is transmitted from a mobile device to a specially configured base station that encapsulates mobile device data packets and sends them to the network via wireless backhaul using an LTE UE modem connection.
1. A system for providing wireless access within a vehicle, comprising:
an in-vehicle base station for providing access to mobile devices, the in-vehicle base station connected to an operator core network via a first and a second wireless backhaul connection, wherein the first wireless backhaul connection is a lower-bandwidth mobile wireless backhaul connection and the second wireless backhaul connection is a higher-bandwidth wireless backhaul connection; and
a coordinating node coupled to the in-vehicle base station via the first and the second wireless backhaul connection;
wherein mobile device data packets are double encapsulated into a first data tunnel and a second data tunnel to be sent over the first wireless backhaul connection, and
wherein a source network address of the first data tunnel is translated at the in-vehicle base station to an address assigned to the in-vehicle base station by a first mobility anchor node in a core network of the first wireless backhaul connection,
thereby enabling mobile device handover between the first wireless backhaul connection and the second wireless backhaul connection.
2. The system of claim 1 , further comprising an ePDG located at the coordinating node, a Wi-Fi UE, and an additional IPsec tunnel between the Wi-Fi UE and the ePDG.
3. The system of claim 1 , wherein the endpoints of the first data tunnel are the in-vehicle base station and the first mobility anchor node, and the endpoints of the second data tunnel are the in-vehicle base station and the coordinating node.
4. The system of claim 1 , wherein mobile device data packets are encapsulated into a third data tunnel to be sent over the second wireless backhaul connection, and where the endpoints of the third data tunnel are the in-vehicle base station and the coordinating node.
5. The system of claim 1 , wherein the source network address of the first data tunnel is translated to a network address of the in-vehicle base station assigned by the first mobility anchor node of the in-vehicle base station for the lower-bandwidth mobile wireless backhaul connection.
6. The system of claim 1 , wherein at least one mobile device of the mobile devices is a UE, and wherein the UE is anchored to a second mobility anchor node, the second mobility anchor node being a packet data network gateway (PGW), the second mobility anchor node being accessed via the coordinating node as a gateway.
7. The system of claim 1 , wherein the second mobility anchor node is the first mobility anchor node.
8. The system of claim 1 , wherein the in-vehicle base station is configured to permit handover of the first wireless backhaul connection from a first eNB to a second eNB.
9. The system of claim 1 , wherein the in-vehicle base station is configured to permit handover from the first wireless backhaul connection to the second wireless backhaul connection.
10. The system of claim 1 , wherein the lower-bandwidth wireless backhaul connection is an LTE UE connection via an LTE macro eNodeB to an LTE core network, and wherein the in-vehicle base station is assigned an IP address via a packet data network gateway (PGW) acting as a mobility anchor node in the LTE core network, and wherein the source network address of the first data tunnel is translated to the PGW-assigned in-vehicle base station IP address.
11. The system of claim 1 , wherein the first and the second data tunnels are an ESP-UDP IPsec tunnel and a GTP-U tunnel.
12. The system of claim 1 , wherein the second wireless backhaul connection is via a base station with Ethernet or fiber wired backhaul.
13. The system of claim 1 , further comprising a plurality of in-vehicle base stations configured to provide Wi-Fi access inside the vehicle on a plurality of channels.
14. The system of claim 1 , wherein the vehicle is a train, a subway, a plane, a boat, a ship, a bus, or a drone.
15. The system of claim 1 , wherein the coordinating node is configured to check IMSI of mobile device to determine whether an IP address should be preserved, and configuring the in-vehicle base station for encapsulation.
16. The system of claim 1 , wherein the in-vehicle base station is configured to use the second wireless backhaul connection when within range, the second wireless backhaul connection providing access from a location in a train station.
17. The system of claim 1 , wherein multiple Wi-Fi access points are mounted within a plurality of train cars, wherein the multiple Wi-Fi access points are configured to form a single mesh network, and wherein the multiple Wi-Fi access points are configured to share access to the second wireless backhaul connection when one or more of the Wi-Fi access points are within range of the second wireless backhaul connection.
18. The system of claim 1 , wherein the in-vehicle base station is configured to permit handin and handout of Wi-Fi devices to and from other Wi-Fi networks via an evolved packet data gateway (ePDG) functionality at the coordinating node.
19. The system of claim 1 , wherein the in-vehicle base station is configured to permit handin and handout of LTE UE devices to and from other cells.