2010-10-19 Current and Future Trends in Hybrid Cellular and Sensor Networks Yongjun Liu, Bin Zhen, Yong Xu, Hui Yang, Betty Zhao yongjunliu@huawei.com www.huawei.com ETSI TC M2M Workshop 19-20 October 2010, Sophia Antipolis, France HUAWEI TECHNOLOGIES CO., LTD.
Contents M2M applications Two types of applications Examples: smart energy, automotive services Hybrid Cellular and Sensor Network (HCSN) M2M architecture Four modes of HCSN architectures More discussions on gateway mode and relay mode for example Conclusions HUAWEI TECHNOLOGIES CO., LTD. Page 2
M2M Applications Two categories M2M applications Type I: general concerns Main challenge: very large amount of devices Type II: stringent QoS requirements Main challenge: higher QoS than current cellular provision Smart home Transformer monitoring and control mhealth ereader e-commerce Smart energy Power line monitoring Automotive services Plant control HUAWEI TECHNOLOGIES CO., LTD.
Smart Energy Thousands to tens of thousands devices/cell Aggregators help to decrease system cost and traffic/signaling burden Not very high QoS requirements usually Low power: no mains power in some cases, e.g. gas metering, water metering Operator network Smart metering Home automation Load control Demand response HUAWEI TECHNOLOGIES CO., LTD. Page 4
Automotive Services Plenty of usages provided by automotive services In vehicle: in-car environment monitoring and ctrl; entertainments V2V: crash avoiding; inter-car communication V2R: broadcast info; emergency call Stringent latency requirement in some cases OnBoard Unit 1. Antenna 2. Mobile Router 3. Vehicle Host 4. Vehicle Gateway 5. Sensor 6. ECU 1 2 3 4 5 6 Operator network HUAWEI TECHNOLOGIES CO., LTD. V2V Interface (DSRC, e.g. WiFi) 1-7 Road Side Unit 1. Antenna 2. Sensor 3. VMS 4. Road side Gateway 5. Access Router 6. Road side Host 7. Border Router V2R Interface (DSRC, e.g. WiFi)
M2M System Architecture Cellular network: remote connection large capacity large coverage high quality WSN (Wireless Sensor Network): local connection low power low cost ad hoc Cellular network and WSN: co-existence cooperation convergence HUAWEI TECHNOLOGIES CO., LTD. Page 6
Hybrid Cellular and Sensor Network (HCSN) Necessity Complementary: WSN-low cost, low energy, ad hoc, cooperative sensing; Cellular-remote connection, large and smart pipe New commercial model: WSN brings out lots of new services, e.g. mhealth, intelligent transportation, Smart home Management requirements: strong capabilities in security and network management for Cellular network Feasibility Key technologies maturating: gateway, platform, uniform system design Standardization: Four modes Standards for whole system architecture: ETSI M2M, CCSA TC 10 More and more liaisons among standard organizations Gateway mode, Dual radio mode, Direct connection mode, Relay mode HUAWEI TECHNOLOGIES CO., LTD. Page 7
HCSN: gateway mode Cellular and WSN are connected by dual radio Gateway(s) One side is shielded by gateway from the other side WSN based on unlicensed frequency bands Least modification to Cellular or WSN No direct mgmt for WSN. WSN can be managed on application layer Hard to control interference to the WSN, so no strict end to end QoS Operator network Cellular link WSN link HUAWEI TECHNOLOGIES CO., LTD.
HCSN: dual radio mode Each node is equipped with dual radio for Cellular and WSN Each terminal can be seen by the Cellular WSN based on unlicensed frequency bands Direct ctrl and mgmt for terminals Multiple routes for service data: through direct cellular connection or through WSN Operator network Cellular link WSN link HUAWEI TECHNOLOGIES CO., LTD. Page 9
HCSN: direct connection mode Each WSN node directly connects to the cellular network Local direct connections between WSN nodes may not exist All nodes are based on the licensed frequency bands End to end QoS is assured by cellular network Directly ctrl and mgmt for terminals Air interface may require improvement between cellular BS and WSN node (concerning large amount of connections and decreasing the cost and power consumption) Operator network Cellular based WSN link HUAWEI TECHNOLOGIES CO., LTD. Page 10
HCSN: relay mode Cellular and WSN are connected by relay node(s) Both sides can be seen by the other side WSN can be based on licensed frequency bands Easy to assure end to end QoS and control interference Easy directly ctrl and mgmt for terminals Low power and low cost can be easier achieved New air interface may be required between relay node and WSN node or cellular BS in some scenarios Operator network Cellular based WSN link HUAWEI TECHNOLOGIES CO., LTD. Page 11
HCSN: PROs and CONs Summary System change End to end QoS Direct ctrl & mgmt Low power Low cost Gateway Dual radio Direct connection Relay More is better HUAWEI TECHNOLOGIES CO., LTD. Page 12
More Discussions on Gateway Mode HCSN Traffic model for aggregator Gateway schedules and shape traffic in both sides. Its behaviors should be considered in network optimization Adaptation between Cellular link and WSN link Appropriate cellular link for gateway to match the WSN link Data scheduling may be affected by sleeping WSN nodes Interference mitigation Interference between cellular and WSN due to out of band emission and imperfect filter. E.g. TDD band 40 (2.3~2.4GHz) and 2.4GHz ISM band (2.4~2.4835GHz) IP-based WSN should be considered From the cellular side, gateway can be seen as a terminal carrying multiple IPs Service enabler and middleware May need a common agreement on application level mgmt: security, devices mgmt, services mgmt HUAWEI TECHNOLOGIES CO., LTD. Page 13
More Discussions on Relay Mode HCSN Lower system cost Uniform RF, baseband and higher layer air interface design consideration for both cellular side and WSN side Resource coordination Uniform time and frequency resource arrangement between cellular network and WSN Multi-hop time synchronization New signaling for WSN nodes WSN mgmt and ctrl within cellular network layer (e.g. NAS signaling for WSN) End to end QoS Assurance For multi-hop route Route (re-)selection HUAWEI TECHNOLOGIES CO., LTD. Page 14
Conclusion Two types of M2M applications Type I: main challenge is large amount of devices Type II: main challenge is higher QoS than current cellular network provision HCSN for M2M M2M applications call for convergence of Cellular and WSN Four architecture modes are analyzed, and each is suitable for some types of applications HUAWEI TECHNOLOGIES CO., LTD. Page 15
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